Pigging Launcher

Description

1. Overview of Pigging Launcher

The Pigging Launcher is generally used for pipeline cleaning. It is important to process equipment for receiving and sending pigs. The transceiver designed and manufactured by our company fully meets the requirements of pigging and line cleaning. The main technical performance characteristics of the overall structure of the company’s transceiver are described as follows: So if you have any other questions, please contact our professionals to answer them for you.

2. Technical parameters:

1) Design pressure: pn1.6-16mpa (35MPa).
2) Design temperature: 60 ℃.
3) Test pressure: the water pressure is 1.5 times the design pressure.
4) Nominal diameter: dn80-dn1400.
5) Corrosion allowance: 2mm.
6) Seismic fortification crack degree: 7 degrees.
7) Applicable media: petroleum, product oil, chemical raw materials, water, and natural gas.
8) Design service life: 30 years.

3. Technical features:

The transceiver includes a quick-opening blind plate, cylinder body, reducing joint, straight pipe section, process nozzle, saddle support, etc. The quick-opening blind plate includes a blind plate cover, cylinder flange, safety interlock device, opening and closing mechanism, and support frame. The safety interlock function of the blind plate is composed of the safety lock plate and the pressure relief device.
The pig launcher adopts an eccentric flat bottom reducing joint. Concentric reducers work for the ball receiver. The maximum protrusion in the reducing joint shall not exceed 0.3mm.

4. Material characteristics:

The materials of the transceiver shall meet the requirements of strength, operating medium and ambient temperature. It should also meet relevant specifications (the latest versions of GB150, hg20581, GB12459, and gb6654).
Sealing material: oil-resistant fluororubber is integrally molded.

5. Protection features:

Because the transceiver is in the open air. Therefore, molybdenum disulfide grease, graphite engine oil or graphite powder shall be coated on the flange connecting parts, the connecting bolts of the bracket, the connecting parts of the quick opening blind plate and the transmission parts to prevent corrosion.

6. Design scheme of transceiver:

1) Design pressure and temperature

(1) The design pressure shall not be lower than the maximum operating pressure.
(2) Design temperature: the design temperature is under normal working condition. The maximum and minimum temperature that the metal of the piping system may reach.

2) The cylinder design shall comply with GB150

3) General requirements

(1) Meet the specified strength requirements at the design temperature and pressure. So its use is safe and reliable.
(2) The equipment shall be able to bear the impact load generated by the pig during pipeline pigging.
(3) The equipped quick-opening blind plate shall be flexible and convenient in opening and closing and reliable in sealing.
(4) The appearance of the equipment is beautiful.

4) Strength calculation

(1) Firstly, strength calculation shall be carried out according to GB150.
(2) Then the coefficient of the welded joint is Ф= 1。
(3) Stress concentration caused by bearings, piping, and internal and external accessories. We should reduce such local stress by using backing plates and reinforcements. And it shall meet the specification requirements.

5) Manufacture

The manufacture of the receiving and sending spherical cylinder shall refer to the relevant provisions of GB150 pressure vessels. The manufacturing, inspection and acceptance of equipment shall also meet the requirements of design documents and drawings.

6) In addition to complying with GB150, the following requirements shall also be met:

(1) The welder qualification shall be in accordance with the supervision regulation on the safety technology of fixed pressure vessels.
(2) Butt welding joints of the shell shall adopt the welding forms specified in GB / t985.1 or GB / t985.2. The welding method and groove shape selected during welding shall ensure full penetration of the welding joint. Defects such as incomplete fusion, incomplete penetration, and cracks at the root of the weld are not allowed.
(3) All butt welding grooves must be machined.
(4) Weld reinforcement shall meet the requirements of GB150.

7. Pigging operation procedures for receiver and launcher

1、 Pigging method: use the receiver and launcher of the station to send the pig. It relies on the back pressure generated by compressed air (or online media). This keeps a pressure difference of 0.1 ~ 0.3MPa at both ends of the pig. It runs at a speed of 0.5-1 M / s. It pushes the pig to move from the head end to the end. So this can achieve the purpose of pigging.

Preparation before Pigging

1. Comprehensively inspect the pigging process facilities on site. It can be in good condition. Check whether the electronic pig and electronic positioning receiver (mechanical and electronic) are in good condition.
2. The operators are proficient in the operation process of serving and receiving the ball.
3. Understand the detailed geographical environment and trend of the pipeline. And preset monitoring points at suspected positions where jamming may occur. (elbow, reducing, crossing and crossing point).
4. The whole process of the pigging operation. We should achieve unified command and unified operation.

8. Regulations on the use of pig

1. Replace the cup according to wear.
2. Before each pigging. The operator must check whether the screws and nuts of the pig are loose.
3. Batteries of electronic positioning transmitter and receiver must be taken out after use. This is to prevent the battery from corroding the electronic components of the transmitter and receiver when placed for a long time.

Pig-sending process:

1. Firstly, check whether the readings of the pressure gauges of the Pigging Launcher and receiver are accurate. Check whether the wear of the pig’s leather cup is consistent
Comply with the use regulations of pig. Check and adjust the electronic transmitter and receiver. Which makes it in good operating condition.
2. Secondly, open the vent valve and blowdown valve of the receiver. And recheck and confirm.
3. Close the vent valve, blowdown valve and air inlet valve of the launcher.
4. Remove the safety interlock device of the quick opening blind plate of the launcher. Open the quick opening blind. We send the pig to the reducer of the launcher. And push the pig firmly. Which makes it in a sealed state.
5. At last, close the quick opening blind. Install the safety interlock device. Slowly open the air supply valve. Watch the tee
The pressure gauge of. The pressure of the launcher slowly rises until the pig sends out. (use the receiver to check whether the pig sends out or sees the action of ball indicator). Generally between 0.3 and 0.5MPa. Close the air supply valve immediately after the pig sends out. Control the pressure at the end of the launcher at 0.1 ~ 0.3MPa.

Pig receiving process

1. After the pig reaches the pig receiver. (use the receiver to check whether the pig arrives or the ball passing indicator at the receiving end acts). Close the air inlet valves at both ends of the receiver and launcher. At the same time, open the vent valve and blowdown valve of the receiver and launcher. This lowers the pressure gauge to zero.
2. When the pressure at both ends of the receiver and launcher is determined to be zero. Open the safety interlock device of the quick-opening blind plate of the receiver. We open the quick opening blind and take out the pig.

Cause and treatment of pig jamming

There are three reasons for the jamming caused by pigging: first, the pipeline is severely deformed so that the pig cannot pass through. (refers to that the diameter deformation of the pipeline or elbow due to stress or an external force is more than 15%). The second is that the pig may get stuck at the reduced diameter. Third, there are long leftovers in the pipeline. Ball clamping at elbow and tee. Solution: gradually increase the pressure difference between the front and rear of the pig. Release the ball jam. Immediately reduce the pressure to 0.1 ~ 0.3MPa after releasing the ball jamming. If the pressure is increased to the design pressure of the pipeline, the blockage cannot be removed. Finally, we use the electronic positioning receiver to find the jamming position accurately. Open the pipe and unblock it.

HSE precautions

1. Strictly follow the “pigging arrangement”. Personnel irrelevant to pigging are not allowed to enter the receiver launcher area. So as to avoid operation accidents.
2. All pigging personnel and on-site operators shall wear labor protection.
3. The cleared dirt shall not be discarded at will. Sewage shall not be discharged at will.

Quality and technical guarantee

1. Firstly, focus on the pigging leading group. The division of responsibilities, rights, and interests is clear. Cooperate closely. Operators shall be under unified command. Unified transfer.
2. Secondly, establish a quality assurance and supervision system. Three Supervisions are adopted. “The first is management supervision, the second is technical supervision, and the third is construction supervision”. Remove all hidden dangers that may affect the pigging quality.
3. Then timely and accurately determine the jamming position during pigging. Such as problems caused by the original state of the pipeline or other reasons.
4. Strictly control the quality. On the premise of safety and reliability, ensure the pigging effect.
5. Strictly control the construction. Implement the whole process under the supervision of the quality and safety supervisor.
6. At last, before construction, workers must check all construction machines and detectors. This is to ensure that nothing is wrong.