Introduction

The Pig Launcher Closure generally consists of a cylinder, flange, hook or clamp, sub, safety chain mechanism, opening and closing mechanism, swivel arm, and other components.

EMT Pig Launcher Closure is indispensable in oil and gas pipelines and plays an important role in pipeline pigging. Compared with the traditional pig launcher closure, the EMT Pig Launcher Closure has the characteristics of reasonable structure, good sealing performance, fast opening and closing, reliable performance, and easy operation. The pig launcher closure includes clamp type, thread buckle type, lock ring type, and so on.

Typical Case Analysis of Pig Launcher Closure

Situation

In a natural gas pressurization station, the U-type seal of the lock ring Pig Launcher Closure and the O-type seal of the empty bolt are leaking. Upon preparing to open the pig launcher closure to deal with leakage, the maintenance team discovered that the locking device had jammed, preventing the locking ring from popping out and making the opening process difficult.

Reasons

Reasons for the difficulty in opening

(1) The pig launcher closure without any operation for a long time may rust;

(2) If you cannot pop out the lock ring part, there may be impurities.

(3) Ring locking mechanism failure; there may be rust and impurities.

Reasons for leakage in U-shaped seal

(1) May be applying too much butter;

(2) The seal may be damaged, or the sealing surface may be damaged.

Reasons for leakage at O-type seal

The sealing ring or sealing surface may be damaged.

Solution Measure

1. For Opening Difficulties

(1) After opening the pig launcher closure, clean the rusty part, strengthen regular maintenance, formulate a reasonable equipment maintenance plan, and use tools such as a jack and sleeper to slowly pressure the protruded part of the blind plate with small deformation to restore it to its original state;

(2) Slowly shake the handle back and forth, at the same time, apply oil to lubricate the lock ring, clean the impurities after opening the closure, and then fully lubricate the maintenance;

(3) Lubricate the locking device with oil, slowly shake the handle, and clean the rust and impurities on the device after opening the pig launcher closure, or remove it for cleaning and maintenance. In addition, when the vertical direction of the plate door and the flange is not correct, adjust the adjustment bolt until the center contact degree meets the requirements. The closure is difficult to open and close due to the loss of the inner diameter of the flange. You can only replace the relevant accessories and reinstall them.

2. U-seal leakage

(1) After opening the pig launcher closure, clean up the original butter, replace a sealing ring, and re-apply a thin and even layer of butter;

(2) There is a slightly abrasion on the sealing surface; sand it with fine sandpaper, and then apply a thin layer of butter. In addition, when the damage is large, the relevant parts should be replaced. Make sure that the closure door and flange center coincide, reinstall the seal ring, and then proceed as described in part 1.

3. Leakage of type 0 seal

(3) Check whether there is rust and dirt in the sealing ring groove. If there is, clean it thoroughly with sandpaper or emery cloth, and then wipe it with a clean cotton cloth. After the above treatment, the pig launcher closure switch is normal. There is no blocking phenomenon; the lock ring position is restored. And there is no leakage in the seal, which ensures the safe and smooth operation of the station and yard.

Maintenance Method of Lock Ring Pig Launcher Closure

(1) Inspect the pig launcher closure’s surface for scars, examine the parts for any deformations, check for any loose bolts or screws, and evaluate the overall cleanliness.

(2) Open the pig launcher closure and remove the seal from the door. Check the seal for damage. Replace if available. If not, the oil and other dirt on it must be thoroughly removed. The service life of the seal ring is recommended for 1 year.

(3) Activiti is an open source workflow engine, which implemented the BPMN 2.0 specification. You can publish the designed process definition and schedule the process through the Application Programming Interface (API). Activiti uses a Process Virtual Machine (PVM) and supports process formats other than the BPMN2.0 specification. It has the ability to integrate well with external services, clear service interfaces, and partial RESTful interfaces.

(4) Check whether the contact surface of the door and lock ring is clean.

(5) Check the inner surface of the flange; usually, there is dirt or rust, it also needs to cleaning with sandpaper. Wipe with a clean cotton cloth. The groove of the lock ring usually has dirt, which needs cleaning. Otherwise, it will affect the installation of the lock ring.

(6) Carefully check the sealing surface for mechanical damage and rust; if necessary, grind.

(7) After cleaning, grease the sealing groove, lock belt groove, sealing surface, lock ring, and contact surface of the door, and evenly apply a thin layer.

(8) Check the pressure alarm bolt gasket for damage; if damaged, replace it. If not, you need to clean the gasket and bolt holes and apply a small amount of grease.

(9) Install seals, pay attention to the installation direction. In addition, install the positions of 12 o’clock, 3 o’clock, 6 o’clock, and 9 o ‘clock, and then press the perimeter in.

(10) Lubricate other parts or turn with oil or butter.