Dual Stage Pressure Relief Valve

Abstract

The present invention provides a two-stage pressure relief valve for relieving pressure. The pressure relief valve consists of a body, poppet bulb, pilot piston and poppet cap. The body defines a main channel extending from the first opening to the second opening. The poppet bulb defines a first flow passage in fluid communication with the main passage. The pilot piston defines a reset passage in fluid communication with the first flow passage of the poppet bulb. The cover channel has a larger diameter than the reset channel. The poppet cap defines a cap passage in fluid communication with the reset passage that guides the piston, and the cap passage is in fluid communication with a pressure chamber defined by the poppet cap and the end of the body.

Description

technical field [0001] The present invention relates to dual stage pressure relief valves and methods, and more particularly to systems, methods and devices for relieving pressure within an inflatable plug. Background technique [0002] It is generally known that pipes transport a fluid (liquid or gas) a certain physical distance within the internal passages of each constituting pipe section. The pipe sections usually run underground and are therefore not easily accessible. [0003] Inflatable plugs are used to repair pipe sections. During inflation, the inflatable plug may exceed a pressure threshold. Current systems typically employ pressure relief valves to relieve pressure within the plug that exceeds an upper pressure threshold. [0004] Conventional inflatable plugs use a single-stage pressure relief valve to relieve pressure within the plug. Using a single stage pressure relief valve to relieve pressure within an inflatable plug has several disadvantages. For exa...

AI Technical Summary

Problems solved by technology

However, where the pressure within the plug exceeds the pressure threshold by a significant amount, the flow rate will be greater

Single-stage relief valves also have large pressure hysteresis and are susceptible to environmental plugging

Images