Installation Instructions for High Pressure GRE Line Pipe Contents !"#
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Preface
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Chapter I Storage and Transportation
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Packaging
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Inspection
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Loading and Unloading
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Storage
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Transportation
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Chapter II Tools and Equipment
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Tools and Equipment for Installation of High Pressure GRE Line Pipe
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Tools and Equipment Used for Field Thread Bonding and High Pressure Maintenance System
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Chapter III Installation
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Personnel
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Stringing Pipeline Along the Ditch
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Joining
)
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Torque
%$Chapter IV Cutting and Taper Milling
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Cutting
$"
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Taper Milling
$"
"
Installation of Field Thread
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Curing Time of Adhesive
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Heating method for Adhesives
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Chapter V Joining with other Systems
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Threaded Adaptors
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Crossovers for Different Threads
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Flanges
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Chapter VI Buried Installation
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Ditch Preparation
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Rocky Areas
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Page 1 of 2 7
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Road Crossing
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Backfilling
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Work in Winter
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Chapter VII Installation of Thrust Blocks
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Thrust Block
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Fixed Support
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Chapter VIII Maintenance of High Pressure GRE Pipelines
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Flanges
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Repair Collar
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Moving Joint for Repair
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Field Thread with Flange
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The Entire Pipeline with Flange
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Chapter IX Line Proof Test
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Frequency
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Filling the System with Water
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Pressurization
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Safety Precautions
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Chapter X
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Transportation of Gases
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Surface Transportation
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Buried Transportation
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Joining the Pipelines
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Page 2 of 2 7
Preface This Instruction provides guidelines for installation of high pressure Glassfiber Reinforced Epoxy (hereinafter referred to as“GRE”) line pipe manufactured by Shengli Oil Field Xinda Guanye Science and Technology Development Co., Ltd. (hereinafter referred to as “Xinda”) and relevant precautions to be taken. It is strongly recommended by Xinda that all installation personnel, prior to installation of the GRE pipes produced by Xinda, should thoroughly read this Installation Instruction and receive field training and or installation training. Please contact the installation dept. of Xinda for any specific issues. The GRE pipes and fittings produced by Xinda are standard series products.
Xinda will
be exempted from any liability for any personal injuries, property losses or civil disputes caused by unauthorized alterations to the products or use of the products to other systems beyond Xinda pipe systems, in which case all warranties of Xinda will become void. ! Safety
Warnings
This is a very important safety warning sign. Please take notice when this sign appears at any processing position or operation procedure, so as to prevent personal injuries. !
Attention
GRE pipeline may carry toxic substances while running under high pressure, so it is of ultimate importance for the operators to observe the regulations herein. Accidents may happen due to improper installation. In order to prevent personal injuries, all the operators must read user instruction to adhesive agents, heater band, propane torch, electric saw and other tools, and work as instructed. If necessary, the operators should wear working suits, gloves, and safety goggles. In addition, the worksite should be clean and tidy with good ventilation.
Page 3 of 27
Chapter I - Storage and Transportation 1. Packaging
The threaded pipes should be packed to bundles at shops prior to shipment. Each bundle should be bound with 4 or 6 rounds of batten along the length of the pipes and fastened with metal strap. Leave the separator boards between the pipe layers. Place wooden pads beneath the two rounds of batten in the center to facilitate handling with forklift (see Fig.10). The nominal length of pipe with thread protector is about 9m to 9.2m, so in order to prevent uneven force on upset end of inner thread or abrasion between pipe ends, two adjoining lines of pipe are staggered in length direction; so the transportation length of each bundle is 9.50m, slightly longer than the length of the pipe. 2. Inspection
After goods arrive at the destination, inspect visually the package of the pipes for any damages. In the event that there are any damages to the packages or loose packs, then inspect the pipes one by one, and see if there are any local discolorations or layering on the outside surface of the pipes. The damaged pipes or fittings should be indicated on the delivery order; the shipping company should be notified of the damage and should retain the damaged pipes at their original state, so the representative(s) of Xinda may conduct inspection. 3. Loading and Unloading
It is recommended that the bundled pipes of various pressure ratings be loaded and unloaded with forklift (see Fig. 1.1). If the forklifts are not available, then remove the packing wooden batten and unload the pipes manually one by one. The high pressure pipes of 10MPa and over can be unloaded using hanging strip or winch, or by a spreader bar between two slings. When unloading with hanging strip or sling, lift by at least two points and be very careful; the space between two strips or slings should be 2.4m to 4.5m. Do not use steel wire to directly bind the pipe or use iron hook to lift; do not throw the pipes or fittings down to the ground from trucks or trailers. Pipe layers on the ground should be separated with wooden boards to avoid point load or damage by squeezing. 4. Storage
Pipes should be stored on flat front or on racks, and there should be at least 4 boards placed under the pipes, whose width should be 90mm at least. Average pipe racks may cause point load, which will damage the pipe (esp. pipes of 7MPa and below). So in order to prevent point load, use 50mm !100mm wooden boards on flat ground as pipe racks. In order to prevent too much weight on the two end connections or on couplings, place a wood lath of at least 25mm thick under every two rows of pipes. If the wall thickness of the connection is over 25mm, then use a thicker lath. The laths put under the pipes should be placed evenly to prevent the pipes from bending. In case of long term storage, the pipes should wear thread protectors and be covered with canvas to avoid UV degradation, mechanical damage or damage to the threads.
Page 4 of 27
5. Transportation
When transporting the pipes to the installation site, use flat bed trailers with wooden floor or use steel pipe trailers with 4 to 6 pieces of wood boards across. If the trailer is not long enough, then the length of the pipe hanging off the trailer should not be over 1.2m (see Fig.1.2). Prior to transportation, use hessian rope, nylon rope or soft belt to fasten the pipes; do not use metal ropes like steel wires or chains, etc.
图 1.0
图 1.1
图 1.2
Chapter II - Tools and Equipment Prior to installation, get ready the taper milling machine, expanding plug corresponding to pipe diameters, circular mold for field use, fittings, strap wrenches, Top thread sealant, whole set of adhesives, etc. 1.
Tools and Equipment for Installation of High Pressure GRE line Pipes
1) Wrenches and tongs (1) Strap Wrench
Do not exert force abruptly when using strap wrenches to prevent crush on pipe walls; care must be taken especially for products with low pressure ratings and thin walls (Fig.2.0). (2) Friction Wrench
Friction wrench (Fig.2.1) is a large-size metal wrench; its jaw is arch-shaped and can wrap around the outside of the pipe at 360 o. The radian of the pipe should be the same as the OD of the pipe. Friction wrench may be used as a supporting wrench. Page 5 of 27
Caution: prior to use, select strap wrenches and friction wrenches, which are suitable for the size of the pipe OD. Refer to Table 2.0. Select and use the recommended tools for products of different specifications. If two wrenches are recommended, then use one of them as the joining wrench, and use the other as supporting wrench. When three wrenches are recommended, then use two of them as the joining wrench, and the third one as supporting wrench. For example, “2B+1C” listed in the table means that two strap wrenches (2B, strap wrench with aluminum handle of 0.6m long) are joining wrenches, and one friction wrench (1C) is supporting wrench. 2) Iron wire brush or scrubbing brush 3) Supports (1) Pipe rack or adjustable pipe support (2) Wooden support or fixed pipe support 4) Fine quartz powder (as detergent powder) or chalk for strap wrench 5) Top thread sealing sealant Xinda suggests that this sealing sealant be used as the main sealant when installing threaded pipelines. See Table 2.1 for doses of this sealant. Customers may use other thread sealant at their own discretion, but the sealant should meet the following requirements as a minimum: * Content of polytetrafluoroethylene:
25%
* Grains of polytetrafluoroethylene: 60mesh to 120mesh (do not use powder material). * Lubricants must conform to components of thread lubricant of API Oilfield Standard. * Lubricants should not be thickened with additives like abrasive powder or clay, etc. All the components of thread sealant should have the same bearing capacity as the pipes under specific application conditions.
图 2.0
Table 2.0 Pipe size (in)
图 2.1
Tools for Installation of High Pressure GRE Surface Pipes 1-1/2
2
2-1/2
3
4
6
8
10
3.5-8
2A
2A
2A
2A
2B
2B+1C
2B+1C
2B+1C
10
2A
2A
2A
2B
3B
3C
2C
3C
14
2A
2A
2B
2B
2B+1C
3C
3C
3C
16
2A
2B
1B+1C
2B+1C
2B+1C
3C
PR （MPa）
Page 6 of 27
18
2A
2B
2C
2C
3C
20
2A
2C
2C
2C
3C
22
2A
2C
2C
2C
3C
24
2B
2C
2C
2C
3C
Note: A: Xinda strap wrench of 0.6m; B: Xinda strap wrench of 1.0m; C: friction wrench. For instance, when installing DN100/PN16 pipes, use one friction wrench as backup, and use two strap wrenches as power wrench; when installing DN150/PN10-16 pipes, use one friction wrench as backup, and use two friction wrenches as power wrench with additional augmentation bar of 2m. The above pipes are suitable for liquid (salt water or crude oil) transportation. Refer to Chapter X for gas transportation. N/A= Not available. Table 2.1 Approximate Dosages of Top Thread Sealant Sizes of Pipe
m/gal
No. o f joints/ gal
1 1/2
1016
113
2
915
102
1
2 /2
813
90
3
711
79
4
508
56
6
305
34
8
230
26
10
145
16
(in)
* Take 9m for the length of each pipe. 2. Tools and Equipment Used for Field Thread Bonding and High Pressure Maintenance System
1) Taper milling machine and relevant expanding plug. The OD of the plug should fit tightly to the ID of the pipeline. 2) Field Thread. 3) Bench friction wrenches or portable friction wrenches. Size of the jaw should be suitable for the pipe sizes, and rubber, cut-off GRE pipe or sealing materials may be placed on the jaw to avoid damage to the pipes. 4) Adjustable pipe support or wheeled pipe racks. 5) Cutting equipment (1) Toothless saw with carborundum or other abrasion-proof materials. If this kind of circular saw is not available which is recommended by Xinda , then the following saws may also be used. (2) Steel handsaw with 32 teeth every inch. (3) Metal wire saw with carborundum or fine teeth. Page 7 of 27
(4) Knife-shaped electric handsaw with carborundum or fine teeth. 6) Thin cord. Used for marking when cutting pipes. 7) Marker with soft end. 8) Hand hammer and wood blocks; used for tapping 3” to 6” bonded fittings and for maintenance of collars.
Chapter III - Installation 1. Personnel
Xinda suggests that all the high pressure pipelines be buried underground. If used otherwise or not installed underground, then contact Xinda for relevant considerations. Due to different conditions, it is difficult to give an exact number of people needed for a specific installation project; in addition, other factors like different pressure ratings and wall thickness may affect the number of people required for the job. But generally, at least three people will be needed for installation of thread-connected pipelines. Xinda will give specific guidance in view of actual field conditions. In most cases, one person will be backup; one person will be in charge of pipe support; if rotary wrench is used to join the pipes, then one person will have to be there to take care of the middle of the pipe to prevent the pipes from moving. The general principle for determining the total number of people needed for the job is to estimate how many people will be needed to make up and tighten the pipes. More people will be needed for installation of pipes with diameters of "4# or pressure ratings of "16MPa. The people needed for joining connections and installation of pipes will be the responsibility of the customers. The field technical personnel from Xinda will only provide technical guidance. 2. Stringing pipeline along the ditch
Attention should be paid to the following when installing GRE pipes underground: 1) In order to avoid too much movement, the pipes should be placed as close to the ditch as possible and on the side with no excavated soil. If possible, the pipes should be put on the outside of the turn-off of the ditch. The direction of the pipes should ensure that the liquid flows from male thread to female thread. 2) If the ditch is not dug yet, determine beforehand on which side the ditch is to be excavated, the pipes to be put on the side with no excavated soil and leave space for the trencher. 3) Before starting installation of pipes, do not remove the thread protectors. 3. Joining
1) Considerations (1) The connection length or insertion depth of joints for pipes of the same specifications should remain consistent. If not, then check the joints and see if they are misaligned or mis-threaded. For pipes with optimized joints, when the outer ring of the
Page 8 of 27
optimized joints of male thread is flush with the end surface of female thread, then it is installed correctly (see Fig.3.0). (2) Warning:
The steel pipe wrenches exert point load, which will cause local stress
and lead to deformation of the pipe walls or an false indication that the pipes are fastened. In this case, Xinda ’s warranties for the quality of the pipes will become void. Friction wrenches with surface jaws or 360 o clamp may be used. (3) Attention: Two or more friction wrenches will be needed for fittings or adaptors of large size or high pressure ratings; chain wrench may also be used in this regard; see Table 2.0. But be careful not to cause point load. The chain on the chain wrench should be adjusted to proper tightness and be perpendicular to the pipe. 2) Preparation prior to joining (1) Remove the thread protectors. When necessary, brush the external and internal threads clean with steelwire brush or scrubbing brush. Check and see if there are any damages to the threads; if any, replace the pipe with a new one. (2) It is of utmost importance to keep the thread clean. Sand or foreign matter may damage the threads, cause sealing failure of the threads, and may also cause false indication that the pipes are fastened tightly. (3) It is easy to align the pipes and threads with pipe rack and wood blocks. If pipes are not straight, they may seem to be ok to be tightened but are actually not. So align the pipes properly before making up. Wood blocks should be placed under the end of the pipe that is to be fixed when making up threads, usually under the internal (female) thread end. Then clamp the pipe tightly from under the end w ith support wrench, and the handles of the support wrench will be on the ground bearing the force. Put another pipe to be joined on the pipe rack. The location of the rack should be about 2/3 of the pipe length to the pipe end to be joined, and then move the rack and line up the pipe (See Fig. 3.1). If rotary wrench is used, then place the pipe rack near the end of the pipe to be joined; align the pipes and threads. 3) Apply Top Thread Sealant TOP thread sealant (Fig.3.2) is specially used for threaded GRE pipelines manufactured by Xinda. Attention: Brand new threads with protectors do not need to be cleaned with solvent before applying Top sealant. However, any oil on the threads should be removed. The operators’ hands, gloves and the tools that come contact with the threads should all be kept clean. Almost all the threads are coated with a layer of rust-proof oil membrane, which should be removed first when connected to steel threads. If there is any doubt that there is oil on the threads, then clean same with solvent. (1) Use TCA, acetone or butanone to remove the oil or dirt on the threads. (2) Attention: On the package of TOP thread sealant is printed its effective date; any sealant beyond that date should not be used. (3) If the male and female threads are washed with solvent, do not apply sealant till the solvent completely dries out. (4) Use the brush accompanying the sealant to apply a thin layer of sealant on the male
Page 9 of 27
and female threads, and remove the extra sealant; the extra sealant built up at the joint may impede flowing of the liquid. 4) Joining (1) Align the external and internal threads manually, make up a few threads first and, if it’s alright, then make up to hand tight, and finally tighten same with proper tool. The best way is to screw the male thread into the female threads. (2) Select proper tool as per Table 2.0, and tighten the joints in the following steps: !
The threads with optimized joint locating ring should be screwed to behind the locating ring and flush with female thread end.
!
When pipes with locating ring and pipes without locating rings are joined together, the way to tighten the joints are:
Attention: When turning the pipelines applied with TOP sealant, keep the torque consistent, which is the approximate value given in Table 3.0. When the pipe continues turning to hand tight point, the torque may increase abruptly. At this time, stop turning and make a mark on the outside of the two ends of the pipe joints along the axis; then tighten the joints according to the requirements below:
* For threaded pipelines of 1 1/2# and 10rd, make up two more rounds when beyond hand tight point or hand tight surface. * For threaded pipelines of 2” to 4”, 8rd, make up two more rounds. * For threaded pipelines of 6” and 8rd
（ 1）
, make up three rounds.
*For threaded pipelines of 8” and 10”, 8rd, when pressure rating is 3.5MPa to 8.5MPa, the male thread should be made up to female thread with 1 to 4 threads left. When pressure rating is 10MPa to 14MPa, the male thread should be made up to female thread with 1 to 2 threads left. During installation, check and see of the connection length of the thread is consistent with the engagement length. If not, or if the engagement allowance is more than 1 round, then remove the joint and clean same, apply new TOP sealant and make up again. Solvent may not be necessarily used when cleaning the joints. If the pipes do not meet the requirement after being rejoined, then replace the pipes. (3) The ways to use the support wrenches (strap wrench may be used as support wrench): $
When using collars, set the support wrench on the pipes.
$
In case of entire pipeline with threaded connection, the support wrench should be
placed about 300mm to 400mm to the female thread, but not placed about 200mm to 250mm to the female thread. (4) Conduct hydrotest promptly after the last piece of pipe is joined. Refer to Chapter IX for the method, requirement and considerations for hydrotest. Refer to the instructions inside the package of thread sealant for the method of using TOP thread sealant and safety precautions. When TOP sealant is used for joining or after the joint is made, make sure that the fittings or joints are not displaced. There are two ways to address this problem: use support wrench to fix the fittings or the joints; and after connection is made, backfill to the fittings or the pipe body on both sides of the joint, or put sand bags on the pipelines. When ambient temperature is below 21
, put the thread sealant inside vehicles or in other
Page 10 of 27
warm places, and use it only when needed. If it’s difficult to apply the sealant, then properly heat the pipe ends warm enough for the sealant to spread easily. Do not over heat. Do not use electric heating strap or chemical heat bags to accelerate the curing of TOP thread sealant.
Fig.３.0
Fig.３.1
Fig.3.2 Table 3.0 Pipe Sizes (in)
Approximate Value of Rotation Torque (Kg$m) Warm weather ( "16
)
（ 1）
Cold weather (＜16
11/2
2.1
2.8
2
2.8
4.2
21/2
3.5
5.0
3
4.2
5.5
4
5.5
7
6
9.0
10
8
10
15
10
15
20
)
* The above are approximate values. Refer to the note (1) below Table 3.1 for the method to determine the torque. 4. Torque
In Table 3.0 and Table 3.1 are listed the torque values required for joining of Xinda GRE line pipes with strap wrenches or friction wrench. Identification of optimized joint pipe Page 11 of 27
Xinda GRE line pipes with optimized joints have a prominent ring of 6.35mm wide at the rear of the male threaded pipe end, i.e. the big end of the thread. Before joining the pipes with optimized joint locating ring, make sure to identify the male and female threads of the pipes by the above method.
Table 3.1
Table of Recommended Torques (Kg $m)
Pipe
Pressure Rating （Mpa）
Sizes （in）
SDC
%3.5
7
10
14
18
22
25
(1)
11/2 2 21/2 3 4 6 8 10
Min.
-
12.4
12.4
12.4
12.4
12.4
12.4
Max.
-
17.3
17.3
17.3
17.3
17.3
17.3
Min.
11.1
13.8
13.8
13.8
13.8
19.4
19.4
Max.
13.8
20.7
20.7
20.7
24.2
27.2
27.2
Min.
-
-
19.4
19.4
20.7
20.7
20.7
Max.
-
-
26.3
26.3
31.1
31.1
31.1
Min.
17.3
22.1
24.2
31.1
31.1
31.1
31.1
Max.
20.7
31.1
34.6
41.5
41.5
41.5
41.5
Min.
27.7
34.6
41.5
41.5
44.9
44.9
44.9
Max.
34.69
47.0
55.3
55.3
58.8
58.8
58.8
Min.
51.8
55.3
62.2
69.1
69.1
-
-
Max.
65.7
69.1
89.9
96.8
96.8
-
-
Min.
65.6
65.6
65.6
65.6
-
-
-
Max.
113.9
113.9
113.9
113.9
-
-
-
Min.
83.1
83.1
83.1
Max.
185.7
185.7
185.7
Note: (1) Values in the table are 75% of the torque at which the female thread failed
(stuck, broken, etc) in approval tests at factory. The test pieces are 8rd or 10rd pipes; the conditions of the test are as below: a. Apply thread sealant on male and female threads. b. Connect the pipe and collar with proper torque. c. The torque value is just what is needed to join the pipes or the collars, not including pipe weight, misalignment or resistance of pipe racks. d. Torque value is measured when rotating the pipes, so torque should be measured when pipes are rotated at worksite. When threads are 100% tightened or engaged, torque value = length of handle perpendicular to the pipe (m) !weight or applied stress(Kg).
Chapter IV - Cutting and Taper Milling 1.
Cutting Page 12 of 27
GRE pipes can be cut using toothless circular saw with carborundum jaw, electric circular saw with fine teeth or handsaw. Xinda suggests that lines be drawn on the outside circle of the pipe first and the cut surface should be perpendicular to the axis of the pipe as much as possible. 2. Taper Milling
Tight fitness of conical surface by Xinda is the key to excellent performance of field threads. Xinda can provide a number of taper milling machines (Fig. 4.0, 4.1). All the tools can grind tapers of 1°43 & ～ 1°56& on pipe ends, which is suitable for installation of field threads and maintenance of high pressure system, also suitable for installation of low-pressure fittings. If protractor or angular ruler are not available on site (which are used for setting angles of blades on taper milling machines), then place the miller machine on the male threads of the pipe, adjust the position f the blades so that the blades are tightly against thread crest, and lock the blade when the angle is set. When taper is milled at the pipe ends, put the field thread on to the tapered end, check the matching of the taper and the length of tapered surface. If the clearance is too large, then cut off the taper head, reset the blade and mill the taper again.
Fig 4.0
11/2 #～6# Ratchet Taper Milling Machine
This is a portable hand tool with expanding plug, used for milling 1 1/2 # to 6 # pipes.
Fig. 4.1
2” to 10” Ratchet Taper Milling Machine
This is a hand tool; in case of too much milling, it can be converted to electric. Pipe systems of different pipe specifications should use expanding plugs of different sizes. 3. Installation of Field Thread
Xinda provides field threads of various sizes to be used for field installation, which will reliably facilitate field installation, adjusting pipeline length and maintenance operations. Page 13 of 27
1) Cut the pipes to the required lengths. 2) Mill the threaded pipe end to be installed on site to the required taper with milling machine. 3) Put the field threads onto the taper surface, cut while trying, till the field thread fully covers the taper surface. The inner taper surface of field tread should be against the taper surface of pipe end but not too tight. Do not force the field thread onto the taper surface. Pipe end should be 6mm shorter than end face of field thread or be flush with it. If the end face of the pipe falls outside the end face of field thread, then cut short the pipe end, generally 6mm shorter than field thread end face. Then re-install and check. 4) Wrap the protective belt on the threads to avoid adhesive. The bonding surface should be clean, clear of any oil, dust or moisture. Clean with solvent when necessary. Once the threads are cleaned, do not touch them any more, because the oil on the hand will contaminate the bonding surface, which will reduce bond strength. Do not use petroleum fractions like gasoline, fuel oils or kerosene as solvent. Do not mix the adhesive until the bonding surface is thoroughly cleaned. There are instructions for use of set adhesive and safety precautions in the package. Read the instructions thoroughly before mixing the adhesive.
Fig.4.2 Field thread
Fig.4.3electric heat belt
Fig.4.4chemical heat bag.
5) Mix the adhesives evenly as per the instructions. (See paras. 1 and 5 of the instruction for curing time and working life). 6) Apply adhesive with hairbrush on the tapered pipe end and the inner surface of field thread and remove the air bubbles. Apply a thin and even layer of adhesive on both bonding surfaces.
Page 14 of 27
7) Put field thread onto the taper surface coated with adhesive, screw up while pushing till it is tight; remove extra adhesive. Be careful that underneath the protective belt and exposed threads should be clear of any adhesive. When field thread is installed, remove the protective belt carefully. If there is any adhesive on the thread, clean same carefully. 8) In cold weather, electric heat belt or chemical heat bag may need to be used to cure adhesive completely. A better practice is to wrap a layer of aluminum foil on the thread, then warm the thread with electric heat belt or heat bag as per instructions. When working in cold weather, Xinda recommends that electric heat belt or chemical heat bags be used to shorten the curing time of adhesives. 9) The dusts or chips produced when cutting GRE line pipes are not hazardous, but they may irritate the eyes, upper respiratory tract or skin. So the worksite should be well ventilated and operators should try not to be exposed to these dusts. Xinda suggests that operators should wear masks and goggles when working with dusts around; wear comfortable cotton working suits to prevent skins from contacting directly with dusts. 4. Curing time of Adhesive
Curing time is the period for adhesive to harden. The length of curing time depends on types of adhesives and ambient temperatures (see Table 4.0); heating will shorten curing time. When ambient temperatures fall below 23 oC, it is suggested that external heating be used to cure. Table 4.0 Ambient Temperatures and Curing Time DS-8000 Series of Set Adhesives Temperatures (oC)
Curing time (hrs)
13
24
16
16
18
11
21
9
24
4.5
27
4
29
3.5
32
3
38
2.5
Table 4.1
Power of Electric Heat Belt
Pipe size (in)
Power of electric heat belt (watt)
11/2
75
2
90
3
155
Page 15 of 27
4
200
6
285
8
315
10
400
5. Heating methods for adhesives
Xinda provides various types of adhesives for bonding field threads. Generally, these adhesives are not easy to cure when ambient temperatures are below 21 o C, and the curing time at 21oC to 24 o C is rather long. So when under 21 o C, the threads should be heated to shorten curing time. Normal adhesives will take 4 to 8 hrs to cure under 21 o C, to 24 o C. The length of curing time depends on the brand of adhesive (see Table 4.1 or Instructions in the package). In most installation projects, 2 to 6 curing time is acceptable, but in some occasions, the adhesive needs to be fast cured. Xinda provides relevant information on heating of field thread in this regard. Xinda can provide two effective heating methods: electric heat belt and chemical heat bag. Electric heat belt can be used repeatedly, using 220-240V power source. Xinda ’s chemical heat bags do not use electricity, but will give out heat by chemical reactions. 1) Electric heat belt (Table 4.3)
Cure the field thread and low-pressure fittings with electric heat belt in the following steps: (1) When field thread is installed, wipe out extra adhesives. Attention: Thread should be clear of any adhesive; may be wrapped up with aluminum
foil or protective belt. (2) The electric heat belt used should be the same size as the pipe size, which should fully cover the joint to be cured. Attention: When heating fittings to be cured, use one size bigger heat belt, for instance, use 4” electric heat belt to warm 3” fittings. (3) Plug the electric heat belt into 220-240v socket and begin warming. (4) All the molded fittings (except flanges)and1 1/2” to 3” field thread should be heated for at least 20min. All the other pipe joints (filament winding and tapered joints) should be heated for at least 30min. (5) Attention: All the field threads and joints should not be applied any stress before cooled down to hand touch, and should not be overbent or tensioned during being heated. If the adhesive is still viscous after being heated once, then do step (4) again.
If generator is used to provide power, make sure that it can provide enough AC power for all the electric heat belts at 220-240v. When generator or other power sources are connected to heat belts through conductor line or additional cables, make sure that the diameter of the conductor line or its across area should meet the total power of the heat belts to avoid over heating. See Table 4.1 for powers required by electric heat belts. 2) Heating with chemical heat bags (See Fig 4.4)
Cure the field thread and low-pressure fittings with chemical heat bags in the following
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steps: Attention: On each package of the heat bag is printed expiry date; no heat bag should be used beyond that date. Wear gloves and safety goggles when mixing the chemical heat bags. Strictly follow the regulations in safety instructions accompanying the heat bags.
(1) When field thread is installed, wipe out extra adhesives.
Attention: Thread
should be clear of any adhesive; may be wrapped up with aluminum foil or protective belt. In
this way, the surface of heat bags can be kept flat, so to prevent the heat bag from falling down into the threads due to the plastic bag being heated. (2) Remove the separating clamp and make a small hole on both sides of the package to eliminate the vacuum. Then use adhesive tape to seal the holes; shake and turn around the package to both sides for at least 25 times till completely mixed. (3) Line up the heat bag with the bonding area of the joint and wrap around the joint. The chemicals inside the bag should be evenly scattered along the length direction. (4) In order to make sure that the chemicals are evenly scattered, flatten the bag with hand when wrapping the bag. Fasten the bag with iron wire. Some joints need two heat bags to cure, such as molded flanges, bonded tapered joints, 4” and 6” field thread. However, two heat bags cannot be used simultaneously; when one bag is used up, then continue with another one. (5) Use the peg on the separating clamp to punch the aluminum boil 3 to 4 times. (6) Inject 10ml water into the bag with the accompanying injector. Inject the water along an oblique angle into the plastic bag through the aluminum foil. Exothermal reaction occurs immediately inside the bag and the heat will come out of the hole made as indicated in above (2). The people at the site should stay 2m away, till the heat reduces (for at least 2 minutes). If package is broken and chemicals spills out but it needs to be cured immediately, then replace the heat bag and repeat the curing process. (7) In cold weather, the heat bags should be kept warm. Wrap the heat bags with insulating layers and make sure that the bags are fully packed. Attention: When ambient temperatures or cold wind temperatures are at 0 oC or below, Xinda
suggests that insulating layers be used to the outside of the heat bags. The insulating
layers are optional, available from Xinda. (8) Usually, the heat from the heat bag can cure the adhesive in an hour, but the length of time depends on the temperature of the products to be cured. (9) Attention: All the field threads and joints should not be applied any stress before cooled down to hand touch, and should not be overbent or tensioned during being heated.
(10) The expired or broken heat bags should be seriously dealt with as per the following steps: $ Wear protective goggles and gloves; $ In well ventilated area, mix evenly the two chemicals in the package or in other vessels.
Mix one bag only every time. $ Use a metal bucket to deal with the chemicals; do not use plastic bucket, because the
heat produced from the treatment may melt plastic bucket. $ After the chemical powders are fully mixed, pour them into a metal bucket and then add
a cup of cold water. $ Wait till the chemicals reacts completely and the heat fully disperses. The residual
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material after the reaction should be pasty. Make sure that chemicals and water are mixed evenly without lumps. If there are lumps, then agitate the remaining material and disperse them, then treat the next bag. $ The method to treat the next bag is the same as above. Attention: The remaining material
after reaction is non-hazardous matter, which can be disposed of like garbage. Remember: Mix only one bag at a time.
(11) Refer to the instructions inside the package for safety precautions.
Chapter V - Joining with other Systems There are some GRE adaptors to be used to connect GRE pipelines to other pipeline systems. 1. Threaded adaptors
There are two kinds of threaded adaptors: bell and male; and its thread type is NPT and 8rd EUE. When connected to steel pipes, check the steel pipes for any burrs. The burrs should be removed; otherwise they will damage the GRE pipe threads. The burrs can be removed by making up and disconnecting steel joints with male and female threads. Attention: If connected to steel couplings with short threads, then cut off a few rounds from the small end of GRE male thread. Cut while trying, that is, cut off two rounds first, then make up and try, till GRE thread does not go beyond the middle of steel collar; there should be a 6mm clearance in between. Or use the data in Table 3.1 to match the length of short thread. See Table 3.1 for the recommended torques for threaded connections. Attention: When GRE thread is connected to steel pipe thread, the GRE thread should not be made up too tightly. GRE threads should be screwed up like brass threads or threads of other soft materials. 2. Crossovers for different threads
Change over can be between NPT, 8rd EUE external offset long form thread, female thread or male thread. Attention: Following are maximum pressure ratings for GRE NPT. 11/2#16Mpa 2# 16Mpa 21/2#14MPa 3#10MPa
4 #1 0MPa 6 #5 .5Mpa 8 #3 .5MPa 10 #3.5MPa
Attention: When pressure applied is too high, then use flange or 8rd long form thread to connect to steel pipe. Page 18 of 27
Note: If temperature fluctuation is over 10 oC or the pressure is equal to or over 16MPa, Xinda suggests that the crossover for GRE pipe end is male thread, and the steel pipe end is female; this is because the linear expansion factor of GRE is larger than that of steel. 3. Flanges
When working pressure is below 3.5MPa, GRE flange should use flat sealing washers of 3.2mm thick and 60-70 Shore hardness (see Fig.5.2). If the washer is squeezed out when tightening connecting bolts on flanges, it indicates that the materials of the washer have low hardness; so washers with high hardness should be used instead. When GRE flange is used together with male flange or marginal valve, spacer washers should be used to prevent GRE flange from being damaged by bending stress. If flange is used under pressures of over 3.5MPa, it is suggested harder washers be used, or special Flexitallic® winding metallic gasket or equivalent sealing gaskets. When fixing threaded bolt into flange screw, both ends of the bolt should be added with a flat washer to prevent flange surface from being damaged when tightening the bolts. Attention: Do not use flange bolt to forcefully join two pipes with ends not closely tightened, otherwise GRE flange thread will be damaged. See Fig.5.3 for tightening sequence of bolts after flange is connected.
Fig.5.1 Crossover for
Fig.5.2 GRE Flange
Threaded Connection
Fig.5.3 Tightening sequence of flange bolt
Chapter VI - Buried Installation 1. Ditch Preparation
The bottom of the ditch should be even and flat; up and downs of the ditch bottom may cause uneven stress on the pipeline; when backfilled, the raised places may cause stress concentration, which will damage the pipeline or cause unnecessary abrasion. When there is pulse pressure inside the pipelines, this is an even more serious problem. Pipelines should be free of sharp corners or abrupt changes in elevations (see data table for minimum bending radius of the pipes). If these are unavoidable, then elbows, vacuum-eliminating valves or check valves may have to be used. Moreover, al the sharp rocks or other abrasive materials should be removed from the ditch bottom (see Fig.6.0). Page 19 of 27
2. Rocky Areas
If pipelines are to cross rocky areas, the pipe ditch should be dug deeper, and the ditch bottom should be placed with a layer of sand or pure soil, and the pipelines should also be covered with sand or soil, which will protect the pipelines against rocks (see Fig.6.1). The backfilled sand and soil around the pipes should be at least 150mm thick 3. Road Crossing
When crossing roads or streams, it is suggested that GRE pipelines be put into steel conduit. If it is not practical to use steel conduit, place contact Xinda and determine the burial depth to prevent ground load from damaging the pipelines. When steel conduit is used to protect the pipelines, the two ends of the conduit should be padded to avoid local stress or abrasion to GRE pipelines. Usually the pipe is protected at the entry and exit with rubber protective jacket or plastic centralizer (See Fig.6.2). the GRE joints inside the steel conduit should also be protected with plastic centralizers or other similar materials. The plastic centralizers should be mounted on pipelines at the coupling or joints every 3 meters. On some occasions (like circulating pressure and high temperature, etc.), more protection may be needed. Customers may contact Xinda regarding fluid media, weight, temperature and other application conditions. 4. Backfilling
When backfilling the pipe ditch, make sure that enough backfill or sand bags is put on the pipe body such that the pipes are fixed; but all the fittings and joints should be exposed for leakage detection by pressure tests. When pressure test is done, the ditch should be backfilled immediately. 1) Time The pipeline system should be backfilled immediately after pressure test is finished, so to prevent pipe movement, displacement or ditch wall collapse due to water hammer.
2) Backfill Soil The backfill soil should be clear of any sharp rocks, gravels, large pieces of soil blocks or frozen soil blocks. Before filling in soil, the backfilled soil under the pipeline must be compacted. Frozen soil, when melted, cannot support the pipeline and will leave spaces around the pipe. Brasque or other tamping devices will squeeze small rocks into pipe walls. So when brasque is used, the pipe must be padded with pure soil. When several pipelines are laid in one ditch, the pipelines should be separated with pure soil or sand of at least 150mm thick. Be sure that the backfilled soil fills all around the pipes. Under no circumstances will there be any clearances below or around the pipes.
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Fig.6.0
Fig.6.1
Fig.6.2 5. Work in Winter If GRE pipelines are to be installed in winter, except observing the regulations above, the following considerations must be followed:
1) In order to prevent the liquid inside the pipelines from freezing, the GRE pipes must be buried below the freezing line. 2) The sealing compound for pipe connection may be hard to apply due to high viscosity in winter; so sealing compound should be better kept at places of high temperatures, and use it when needed. Or properly warm the pipe ends and then apply sealing compound, but the pipe ends should not be over heated. 3) When ditch is dug, immediately install the pipes and backfill. If backfill over the night, then the excavated soil may be frozen on the ground, which should not be used for backfilling, this is because the frozen soil cannot wholly support the pipe and will leave spaces around the pipes. 4) When installing GRE pipelines in swampy area, the work can be carried out in winter after the ground is frozen; at this time, the ditch is relatively stable. Except the abovementioned, the following measures should also be taken: (1) Remove accumulated snow, pulverize or grind floating ice on the ground. The broken ice should be put away from the worksite, so it will not be mixed with the unfrozen soil which will be used as backfill soil. (2) The ditch should be dug to stable soil. If soil at ditch bottom is not stable, then use sand bags or other materials to stabilize the bottom soil, or use metal casing over GRE pipes. (3) When ditch is dug, immediately install the pipes and backfill, but not with frozen soil blocks.
Chapter VII - Installation of Thrust Block 1. Thrust Block
Thrust blocks are needed to bear the forces generated by pipeline direction changes or abrupt changes of diameters to protect high pressure fittings, including elbows and tees. Practices show that this is an effective protective measure and should be taken in installation operations. If GRE pipeline is bound onto steel pipelines, then the steel pipeline must be padded with fixed support. Fittings that need thrust blocks are listed below: 11/2#, 2#, 21/2#
pressure "20MPa
3#, 4#
pressure "16MPa
6#, 8#
pressure "5.5Mpa
10#
pressure "3.5Mpa
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Thrust blocks are usually concrete structure. For 4” fittings or smaller, they should be completely wrapped with concrete of at least 200mm thick. 6” and 8” fittings should be enveloped with concrete of at least 500mm thick. See Fig.7.0 for these two types of thrust blocks. 2.
Fixed Support
When high pressure GRE pipes need to be joined to steel pipes from injection metering station or polymer injection stations, it is required that fixed support be constructed near the joint at the steel pipe side, so as to prevent abrasion due to GRE pipe vibration or leakage of steel pipe joints.
In addition, when crossover is used between GRE pipe and steel pipe, fixed support should be constructed at the steel pipe side near the crossover. The type and standard for steel pipe fixed support will be at customer’s own discretion. Elbow
Vertical view
Tee
Side view
vertical view
side view
Fig.7.0 Typical Thrust Blocks
Chapter VIII - Maintenance of High Pressure GRE Pipelines This Chapter describes the ways to repair damaged pipes and leaking joints. Xinda suggests that the methods mentioned in this chapter be used instead of other methods, so as to prevent safety accidents. Please be noted that fittings should not be repaired once damaged. Other parts of the pipelines, once repaired, must be proof tested before being put into use to verify the reliability of the repaired parts. If you need any help, please contact Xinda Group.
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Prior to starting repair, release the pressure inside the system; do not operate under pressure. In the course of repair, the repaired parts must be kept dry; this is especially important for repairs with adhesives. When temperatures drop down to below 21 oC, it is suggested that electric heat belts or chemical heat bags be used to heat and cure all the places with adhesive. High pressure pipelines can be repaired with the following methods: 1. Flanges
If leaking occurs at the joining area of the threaded collars, then it can be repaired with flanges. This is the simplest way. Cut the collar into two halves along the middle perpendicular to the pipe direction, then disconnect the two halves of collar and mount the flanges instead. 2. Repair Collar
The repair collar is a thick-walled collar of 450mm long, with tapered bells at both ends for adhesion (Fig.8.0). It can be used to repair 1 1/2# to 6 # pipelines with maximum pressures of up to 16MPa. The repair collars can stand 16MPa pressure used for 1 1/2# to 2 1/2# pipes; 14MPa for 3” to 4” pipes and 7MPa for 6” pipes. Despite that repair collars are designed to repair high pressure pipes of 16MPa, but, if pipe sizes are matching, they can be used for repair of low pressure pipes. This repair method can be used for GRE pipes of all specifications. For pipelines of different sizes and pressure ratings, repair collars of various sizes are available for selection. The way to use the repair collars: 1) Pipe ditch for 1 1/2# to 4” buried pipes should be dug 15m longer, and 24m longer for 6” pipelines, so that the repair collar cay be inserted into one end of the pipe. 2) Cut off the damaged part and mill taper at one end of the pipe. 3) Mount collar at the tapered end and make sure they fit tightly. When adhesion is applied, the collar may go in 6mm to 12mm farther. 4) After repair collar is mounted on the tapered pipe end, then put it against the side of the other pipe, and measure the length of second taper to be milled with a tape. The length of the second taper to be milled should make sure that the pipeline fits into the collar perfectly. Prior to applying adhesive, carry out several times, dry fit tests to ensure accuracy of measurement of taper length and the milled taper. When cutting off the damaged part, leave the pipe as long as possible, because the adhesive has some kind of lubrication, which will allow deeper insertion when installing. 5) Apply adhesive on all the bonding surfaces, then lift the tapered pipe or move it aside, insert it into the bell of collar; the taper surface should be tight. 6) When installing repair collar onto the first milled taper, put wood blocks below the other end of collar and strike it with hand hammer. When inserting the second taper into the collar, tight it with sling or pipe tightener. 3. Moving joint for repair
It can be used to repair 2”, 2 1/2”, 3” and 4” pipes, with maximum pressure of 16MPa. The moving joint is a long collar with a moving joint in the middle (fig.8.1), and the way to
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repair the pipe is the same as repair collar. There are conical bell at the both ends of moving joint (2” to 4” pipe), or having 8rd external upset long form thread joint with female thread (2” to 3” pipes). This moving joint is designed to repair high pressure pipes, and can also be used for low pressure pipes and FRP pipes of other specifications, but the sizes must be matching. 1) The way to repair pipes of 10MPa and below is the same with repair collar, but not much pipe is to be exposed; it’s just that the taper milling machine has enough room to rotate and the moving joint can be mounted. 2) In case of repairing 2” and 3” pipes with pressure ratings of 14MPa and 18MPa, Xinda suggests that 8rd threaded moving joints be used together with field thread. (1) Cut off the damaged part, then mill taper at both ends of the remaining pipe, then install field thread as per instruction in Chapter IV. Make sure that the sizes are measured correctly and the moving joint will not stand load after installation. (2) Repair the moving joint as per instructions in Chapter III. 4. Field Thread with Flange
Repair pipes of various lengths and pressure ratings with Xinda ’s universal field thread. After the damaged part is cut off, install field thread as per Chapter IV. Then add collar to the measured pipes or joints, and finally join the pipes with flanges.
5. The Entire Pipeline with Flange
The fastest way to repair threaded GRE pipes is to remove the entire damaged pipe and then join with flange. Excavate the backfill over the damaged pipe, cut the pipe at the damaged area, and disconnect the two halves. If the pipe is connected with threaded collar, then the collar must be removed so as to install flange. The length of the substitute pipe should be approximately the same as that of the damaged pipe. For pipelines connected with integral joint, the repair is usually done by adding short joints, but not cut off the integral joint and then add field thread. The substitute pipe should be a little bit longer than the damaged pipe in order to install short joint. The short joints used for this kind of repair are of different lengths, like 50mm-300mm and 600mm-3000mm.
Fig.8.0
Fig.8.1
Chapter IX - Line Proof Test ! In
order to prevent personal injury and loss of property, pressure tests must be
carried out in strict accordance with the following regulations and procedures. In case of violations of this provision, Xinda’s all warranties to the products will become void, and Xinda will hold no responsibility for any personal injury or loss of property caused thereby. Page 24 of 27
Pressure testing must be carried out before the installed GRE pipelines are put into use to ensure line integrity. During the testing, try to avoid pressure fluctuation or water hammer, because pressure fluctuations and water hammer will generate pressures that are several times or tens of times of the working pressure or pressure ratings of the pipe or fittings. !Do
not use air or other gas to do pressure testing, otherwise very dangerous
results will occur. Please contact Xinda for issues with pressure testing. 1. Frequency
In case of a large or complicated installation project, it is suggested that pressure testing be done when a section of the pipe is installed. Xinda recommends that the first test should occur when the first 300m pipe is installed, so to make sure that the installation techniques meet the requirement. This is also very important for installation people who have not installed the GRE pipelines of the same specs and pressure ratings to know about the installation regulations and procedures, improve their installation techniques and to build up their confidence. Please contact Xinda for any problems. 2. Filling the system with water
Use water as pressure media. The pressure for testing should be the working pressure of the system or the pressure rating of the pipes, but should not exceed 1.25 times of pipe pressure ratings. For pipes that have been 100% hydrotested in Xinda factory, the maximum pressure for testing the pipes after being installed will be the pressure rating of the pipes. When carrying out hydrostatic tests to GRE pipes, the pressure may not stay stable due to sunlight, wind or changes of ambient temperatures, because these factors will cause expansion or contraction of the liquid inside the pipes. If pressure fluctuation is too large, it may be caused by air existing inside the system. In view of safety precautions, hold down the middle of each pipe with sufficient backfill or sand bags prior to pressure testing, but leave all the joints and fittings exposed, so as to detect leakage during testing. If the pipes are not backfilled in situ, or not overlain with sand bags, then do not pressure test. If it is required to install thrust blocks, then the blocks should be constructed and buried before testing. It is very important to pressurize slowly. Please remember: fast pressurization may damage the GRE pipe, because the impact generated by fast pressurization will exert too high pressure on the pipes. 3.
Pressurization
It is recommended to increase the pressure at 0.7MPa per min till test pressure. This rate should not only be kept at the initial testing, but also for pressuring the pipes later (like when the pump is repaired) or for re-pressurizing the pipes after they are put into use again. When pressurized to the test pressure, stop pressurization, and observe for 10min. If pressure drop does not exceed 1% of the test pressure, and there is no leakage at the joints or fittings, then decrease the pressure to the working pressure of the system and hold for 4 hrs;
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conduct visual inspection to the appearance of the pipes; pipes with no leakage will be deemed as up to standard. In case of leakage, the pipe will be pressure tested after repair. 4. Safety Precautions
Please carefully read the following safety considerations: ' Just like any other systems being pressure tested, take proper protective measures
during testing. Pipeline systems should be installed and pressure tested in strict accordance with regulations and procedures; no negligence is allowed; and do not risk people’s lives or loss of properties. ' Xinda suggests that pipelines, after being installed, should not be pressure tested
with air or other gases. GRE pipes are light in weight and are flexible, so the problems of GRE pipes are different from those of steel pipes. In case that air other gas is used for testing, and if it fails, then, due to sudden release of stored energy, the whole system will shake and vibrate. Enormous energy may cause severe personal injuries to the people on site and may cause serious loss of pipelines or other properties. * If customers violate the abovementioned operation regulations and procedures and
safety considerations, or use air or other gas for pressure testing, then Xinda will bear no responsibility for product quality and warranty provisions contained in the contract or for any personal injuries, damages to equipment, pipelines or other individual properties or for any civil disputes caused thereby. If, under some circumstances, air or other gas has to be used as testing media, Xinda will recommend testing methods and safety considerations, so as to minimize the risks; but Xinda
will have no responsibly for any losses or injuries so caused, and the risks relating to
such pressure testing will be borne solely by the customer.
Chapter X Xinda
Transportation of Gases
GRE pipeline systems can carry most of the compressed gases (1), sulfur-bearing
or sweetened natural gases, air, SO 2, N 2, CO 2(2) and H 2S, etc. but care should be taken for the following: 1.
Surface Transportation
If it is planned to use Xinda GRE pipes for surface transportation of gases, please contact and consult this Company. 2. Buried Transportation !
The burial depth of the pipes should be at least 1m deep for buried
transportation.
1) Buried transportation of toxic or inflammable gases If GRE pipes are used to transport toxic or inflammable gases like SO 2, H 2S or methane, etc. Xinda suggests that safety factors be increased, and the pipelines should be carefully designed and installed. The safety factor suggested by Xinda is at least 1.5 times of pipe
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pressure rating (i.e. 1.5:1). For instance, in case of 10MPa working pressure, then the pressure rating of the pipes used should not be less than 15MPa. GRE pipes can be used under pressure ratings, but when transporting toxic or inflammable gases without other special design or safety precautions, then the safety factor proposed by Xinda should be used, and the maximum working pressure should not be over 10MPa.
2) Buried transportation of non-toxic gases Xinda suggests that, when transporting non-toxic gases, a safety factor of 1.25:1 should be used. For instance, if the estimated working pressure is 11MPa, then the pressure rating of the selected GRE pipe should not be less than 14MPa. 3) Buried transportation of solution gas Use 1:1 safety factor in this case; but for every 2% of gas dissolution, the safety factor should be increased by 1%. For instance, in case of 4% of CO 2 solution in the pipe, the safety factor required for the pipe will be 1.02:1. 3. Joining the pipelines
For pipelines carrying high gases, it is suggested that 8rd or 10rd external upset long threaded joint be used. Some other connection methods for pipe joints and the effectiveness of sealing compound are favorable; the application of these depends on the objects, safety factors and industrial specifications. These cases fall beyond the scope of this Installation Instruction. (1) If GRE pipelines are used to carry O 2, please contact Xinda. (2) The present data shows that anhydrite cured GRE pipes cannot be used for transportation of CO2 with over supercritical pressure. Supercritical pressure is defined as 7.5Mpa (1,085psi) at 31 oC.
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