Speed regulated pipeline pig
US8650694B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 2008 |
| Grant date | Feb 18, 2014 |
| Priority date | — |
| Expiry date | Feb 17, 2031 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16L55/38
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A pipeline pig includes a venturi and a modulating valve located rearward of the inlet side of the venturi. When the valve is in the open position, a predetermined maximum bypass flow is allowed through the venturi. The closed position allows a predetermined minimum bypass flow. The valve may be a poppet-style valve or a frusto-conical shaped stopper. The stopper has sufficient mass and/or aerodynamic drag to overcome the spring force holding the valve in the open position. When the pig stalls, the valve closes and the stopper chokes bypass flow through the venturi. When the pig starts running again, the valve opens as inertia forces the stopper away from the inlet side of the venturi. Also, as friction of the pig increases due to changes in the internal diameter of the pipeline or accumulation of debris ahead of the pig, increased airflow across the valve creates drag sufficient to partially overcome the spring force, thus keeping the pig moving at a desirable rate of travel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.