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Results for “RELIEF VALVES”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1969

Relief valve

Relief valve to permit slow and fast bleeding rates at difference pressure levels

Steenken, J.↗
NASA NTRS1970

Inexpensive tamper proof safety relief valve

Basic relief valve has added safety relief valve capability that relieves overpressure before failure can occur. It may be installed in inaccesible areas with a high degree of reliability, constructed from a variety of materials, and adapted to the user's specific application.

Frankewich, P. A.↗
NASA NTRS1968

Dual rate pressure relief valve

Pressure relief valve vents at a slow bleed rate at one pressure level and at a higher bleed rate at a higher pressure level. The value housing contains a sleeve, inlet port, outlet port, an orifice, a ball and seat arrangement, and a belleville spring diaphragm.

Steeneken, J.↗
NASA NTRS2017

Magnetically Retained Relief Valve

A pressure relief valve includes a housing having a fluid inlet and at least one fluid outlet. A first structure mounted in the housing and fixed in relation thereto is in magnetic attraction with a second structure coupled to a piston disposed in a portion of the housing. The piston defines a chamber disposed adjacent to the fluid outlet(s) throughout the piston's stroke. The piston includes a sealing element providing a sealing force to prevent flow through the valve. The sealing force is independent of the magnetic attraction force between the first and second structures.

Johnson, Wesley L.↗
NASA NTRS1986

Damage-Free Relief-Valve Disassembly

Tool safely disassembles relief valves without damage to sensitive parts. Relief-valve disassembly tool used to extract valve nozzle from its housing. Holding device on tool grops nozzle. When user strikes hammer against impact disk, holding device pulls nozzle from press fit. Previously, nozzle dislodged by striking spindle above it, but practice often damaged retaining screw. New tool removes nozzle directly. With minor modifications, tool adapted to valves from different manufacturers.

Haselmaier, H.↗
NASA NTRS1982

Force Augmentation for Relief Valve

Simple design change for poppet relief valve enables flow through valve to exert additional force to help keep valve open. Although originally intended for relief valves for liquid oxygen and liquid nitrogen in Space Shuttle orbiter, concept is applicable to pressure-or flow-actuated valves for wide range of fluids and temperatures.

Luger, J.↗
DOE OSTI2013

Statistical Performance Evaluation Of Soft Seat Pressure Relief Valves

Risk-based inspection methods enable estimation of the probability of failure on demand for spring-operated pressure relief valves at the United States Department of Energy's Savannah River Site in Aiken, South Carolina. This paper presents a statistical performance evaluation of soft seat spring operated pressure relief valves. These pressure relief valves are typically smaller and of lower cost than hard seat (metal to metal) pressure relief valves and can provide substantial cost savings in fluid service applications (air, gas, liquid, and steam) providing that probability of failure on demand (the probability that the pressure relief valve fails to perform its intended safety function during a potentially dangerous over pressurization) is at least as good as that for hard seat valves. The research in this paper shows that the proportion of soft seat spring operated pressure relief valves failing is the same or less than that of hard seat valves, and that for failed valves, soft seat valves typically have failure ratios of proof test pressure to set pressure less than that of hard seat valves.

42 ENGINEERING↗
NASA NTRS2008

Improved Relief Valve Would Be Less Susceptible to Failure

The balanced-piston relief valve with side vented reaction cavity has been proposed as an improved alternative to a conventional high-pressure, high-flow relief valve. The proposed valve would be less susceptible to failure. A typical conventional high-pressure, high-flow relief valve contains a piston that is exposed to the upstream pressure across the full valve-seat diameter and is held against the valve seat and the upstream pressure by a large spring. In the event of an increase in upstream pressure to a level above the valve set point (the pressure above which the valve opens), the opening force on the piston can be so large that the piston becomes accelerated to a speed high enough that the ensuing hard impact of the piston within the valve housing results in failure of the valve. For a given flow cross section, the proposal would significantly reduce the force, thereby reducing susceptibility to failure. A basic version of the proposed balanced-piston relief valve with side vented reaction cavity is described.

Farner, Bruce R.↗
NASA NTRS1988

Relief Valve Opens And Closes Quickly

Relief valve opens quickly to relieve excess pressure and closes quickly when pressure drops slightly below relief pressure. O-ring exposes one or more ports under high pressure, releasing excess pressurized fluid. Adjusting screw used to change compression on Belleville-spring washers and to set pressure at which valve opens. Designed for use aboard Space Shuttle to vent pressurized hydrazine to vacuum, valve concept useful in industrial applications where rapid opening, rapid closing, or low susceptibility to blockage by vented fluid required.

Svejkovsky, Paul A.↗
NASA NTRS1967

Aspirator increases relief valve poppet stroke

Addition of an aspirator to a relief valve increases the valve poppet stroke under dynamic flow conditions. The aspirator allows poppet inlet dynamic forces to overcome relief valve spring force. It reduces the fluid pressure in the skirt cavity by providing a low pressure sense probe.

Biddle, M. E.↗
NASA NTRS2017

Development Specification for RV-346/348 Positive Pressure Relief Valves (PPRV)

This specification establishes the requirements for design, performance, safety, testing, and manufacture of the RV-346 and RV-348, Positive Pressure Relief Valve (PPRV) as part of the Advanced Extravehicular Mobility Unit (EMU)(AEMU) Portable Life Support System (PLSS). The RV-346 serves as the Positive Pressure Relief Valve (PPRV), and the RV-348 serves as the Secondary Positive Pressure Relief Valve (SPPRV).

PPR↗
NASA NTRS2005

8-inch Reflange Inlet and Two 6-inch 600# Flange Outlets Relief Valve Description and Specifications

In the past, an Anderson Greenwood (AG) pilot operated relief valve was used to protect the E-1 rocket engine test facility. It was found that the AG valve is destroyed and discharges internal parts at a great velocity on opening. This is a major safety and cost issue. The solution is a relief valve to match present Anderson Greenwood pilot valve A 8z B dimensions. The valve is to use a precise buckling pin obeying Euler s Law to act as the pressure sensor and actuator. The valve must not self destruct on opening.

Source record↗
DOE OSTI2012

TRACE and TRAC-BF1 benchmark against Leibstadt plant data during the event inadvertent opening of relief valves

In framework of introducing TRACE code to transient analyses system codes for Leibstadt Power Plant (KKL), a conversion process of existing TRAC-BF1 model to TRACE has been started within KKL. In the first step, TRACE thermal-hydraulic model for KKL has been developed based on existing TRAC-BF1 model. In order to assess the code models a simulation of plant transient event is required. In this matter simulations of inadvertent opening of 8 relief valves event have been performed. The event occurs at KKL during normal operation, and it started when 8 relief valves open resulting in depressurization of the Reactor Pressure Vessel (RPV). The reactor was shutdown safely by SCRAM at low level. The high pressure core spray (HPCS) and the reactor core isolation cooling (RCIC) have been started manually in order to compensate the level drop. The remaining water in the feedwater (FW) lines flashes due to saturation conditions originated from RPV depressurization and refills the reactor downcomer. The plant boundary conditions have been used in the simulations and the FW flow rate has been adjusted for better prediction. The simulations reproduce the plant data with good agreement. It can be concluded that the TRAC-BF1 existing model has been used successfully to develop the TRACE model and the results of the calculations have shown good agreement with plant recorded data. Beside the modeling assessment, the TRACE and TRAC-BF1 capabilities to reproduce plant physical behavior during the transient have shown satisfactory results. The first step of developing KKL model for TRACE has been successfully achieved and this model is further developed in order to simulate more complex plant behavior such as Turbine Trip. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
NASA NTRS1964

Sensitive low-pressure relief valve has positive seating against leakage

A pilot-operated relief valve which provides positive seating against leakage in cryogenic systems is described. The principal advantage is that the pilot poppet is unaffected by variations in control pressures in the pilot cavity, and results in a more accurate sensing of inlet pressure conditions.

Source record↗
NASA NTRS1978

Dual relief-valve system

System allows removal and recertification of pressure-relief valve without compromising safety requirements or depressurizing pressure vessels.

Karns, J. R.↗