Expanding gate valve with fluid-powered actuator
US4535967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 1984 |
| Grant date | Aug 20, 1985 |
| Priority date | — |
| Expiry date | Jan 5, 2004 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16K47/00
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An expanding gate valve (10) provided with a piston type pneumatic powered actuator (40) for opening and closing the valve wherein the actuator piston (54) is adapted to be driven by fluid pressure in one direction to operate the valve but is returned by spring means (63, 64) when the pressure is removed. The actuator includes a hydraulic choke means (71) comprising a hydraulic piston (80) and cylinder (72) wherein the hydraulic piston is fixed to the actuator stem (23) and is provided with an orifice (89) which imposes a constant velocity control on the actuator stroke by producing a throttling effect on the hydraulic fluid moving from one side of the hydraulic piston to the other. The hydraulic cylinder (72) is filled with a fluid which maintains substantially uniform viscosity in the range of minus 40.degree. Centigrade to 204.degree. Centigrade whereby the valve is adapted for consistent operation during rapid cycling conditions. The actuator housing (41, 42) is a sealed unit with the exception of a single opening (69) which exposes one side of the actuator piston (54) to atmospheric pressure but which may serve as an inlet for pressurized fluid to convert the actuator to a dou…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.