US 5,625,917 A · Foam pipeline pig with seal cups

Abstract

A pipeline pig having an elongate generally cylindrical bullet-shaped body formed of resilient foamed material having a rear end and a nose portion with a resilient rear seal cup secured to the rear end and a resilient front seal cup secured to its forward end near the nose portion. The resilient seal cups have apertures through their central portions and a circumferential rearward facing peripheral lip configured to engage the inner wall of the pipeline. The propelling fluid pressure is transmitted to the rear cup lip to engage it in sealing relation on the inner wall of the pipeline and passes through the rear cup apertures and is propagated throughout the foam material of the body to radially expand the body and exert a radial force on the front cup lip to radially expand and firmly engage the front cup lip in sealing relation on the inner wall of the pipeline. A portion of the propelling fluid pressure propagated throughout the foam material of the body passes to the exterior of the body to exert a propelling force on the front cup lip downstream from the rear cup lip, and a portion of the propelling fluid pressure propagated throughout the foam material of the body passes through the front cup apertures and is propagated throughout the foam material of the nose portion to the exterior of the nose portion and increases turbulence in the pipeline in front of the pig.

Claims11

Dependent claims

A pipeline pig of the type to be propelled through a pipeline by a pressure gradient exerted by a propelling fluid in the pipeline, comprising in combination:

an elongate one piece cylindrical body formed of resilient foamed material having a rear end a nose portion at a front end;
an apertured rear cup of resilient non-foamed material at said rear end of said body having a circumferential rearward facing peripheral lip configured to engage the inner wall of the pipeline;
and
an apertured front cup of resilient non-foamed material near said body nose portion having a circumferential rearward facing peripheral lip configured to engage the inner wall of the pipeline;
said resilient foamed material of said body being sufficiently porous and said rear cup and said front cup each being apertured such that the propelling fluid pressure passes from said rear cup through said resilient foamed material of said body to said front cup to provide substantially equal sealing pressure to said peripheral lips of both said cups.

2 more elements

A pipeline pig of the type to be propelled through a pipeline by a pressure gradient exerted by a propelling fluid in the pipeline, comprising:

an elongate one piece cylindrical body formed of resilient foamed material having a rear end a nose portion at a front end;
a rear cup of resilient non-foamed material secured to said body rear end having apertures through a central portion and a circumferential rearward facing peripheral lip configured to engage the inner wall of the pipeline;
and
a front cup of resilient non-foamed material secured to said body near said nose portion having apertures extending through a central portion and a circumferential rearward facing peripheral lip configured to engage the inner wall of the pipeline;
wherein
the propelling fluid pressure is transmitted to said rear cup lip to engage it in sealing relation on the inner wall of the pipeline and passes through said rear cup apertures and is propagated throughout the foam material of said body to radially expand said body and exert a radial force on said front cup lip to radially expand and firmly engage said front cup lip in sealing relation on the inner wall of the pipeline;
a portion of the propelling fluid pressure propagated throughout the foam material of said body passes to the exterior of said body to exert a propelling force on said front cup lip downstream from said rear cup peripheral lip;
and
a portion of the propelling fluid pressure propagated throughout the foam material of said body passes through said front cup apertures and is propagated throughout the foam material of said nose portion to the exterior of said nose portion.

6 more elements

Dependencies are inferred from the claim text.

Foam pipeline pig with seal cups

Life of this patent

Foam pipeline pig with seal cups

Life of this patent

Abstract

Claims11