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Safety Relief Valves
Safety relief valves protect pressure vessels, boilers and piping by opening automatically when pressure reaches the set point and closing again once it has fallen. Seven Star LLC supplies safety valves and pressure relief valves in Oman from LESER, Crosby and Anderson Greenwood, together with hydraulic relief valves from KRACHT and Bosch Rexroth. The listed items run from small threaded safety valves to API 526 flanged valves, clean service valves and change-over valves.
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Category guide
About Safety Relief Valves
Safety relief valves protect pressure vessels, boilers and piping by opening automatically when pressure reaches the set point and closing again once it has fallen. Seven Star LLC supplies safety valves and pressure relief valves in Oman from LESER, Crosby and Anderson Greenwood, together with hydraulic relief valves from KRACHT and Bosch Rexroth.
The listed items run from small threaded safety valves to API 526 flanged valves, clean service valves and change-over valves.
Types of safety and pressure relief valves listed
LESER makes up most of the category. The Type 526 is a flanged safety relief valve built to the API 526 dimensions and orifice designations used in refineries and gas plants. The Type 441/442 is the DIN flanged counterpart, common in European-built plants. Threaded valves such as Types 437, 459 and 462 cover small capacities, for example thermal relief, pumps and skid packages, and Types 483 and 488 are designed for clean service in pharmaceutical and food plants. Change-over valves (Types 310, 320 and 330) let two safety valves share one nozzle so that one can be removed for testing while the other stays on line. Crosby JOS-E and OMNI-TRIM valves cover spring-loaded process duty. KRACHT and Bosch Rexroth valves are a different family: they limit pressure in oil hydraulic circuits and are not code safety valves for vessels.
Codes and standards for overpressure protection
Relief devices are sized and built to recognized codes. In ASME plants, valves for unfired pressure vessels follow ASME Section VIII, with sizing to API 520 and dimensions to API 526. European practice uses the Pressure Equipment Directive and ISO 4126. The code determines the allowable overpressure, the capacity certification and the nameplate marking, so the governing code must be stated in the inquiry.
Data needed to quote a safety relief valve
- Set pressure, back pressure (constant and built-up) and relieving temperature
- Fluid, its state and the required relieving capacity, or the orifice letter if already sized
- Inlet and outlet size, rating and flange facing
- Body, trim and spring materials, and bonnet type
- Governing code and options such as a lifting lever or bellows
With an existing valve, the nameplate details and serial number let us check the configuration against the manufacturer documentation. We handle inquiries from across the GCC.
What to include in your inquiry
These details let us quote the right item the first time.
- Set pressure
- Fluid and relieving temperature
- Required capacity or orifice size
- Inlet and outlet size and rating
- Body and trim material
- Code or standard named in your specification
Missing some of them? Send what you have. A nameplate photo or an old part number is enough to start.
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Request a Quote for Safety Relief Valves
Looking for a specific model, part number or brand in Safety Relief Valves? Send us your requirements and quantities. Seven Star LLC sources genuine industrial equipment for customers across Oman and the GCC and replies with a formal quotation.
- Genuine OEM products
- Supply across Oman & the GCC
- Formal quotation from our sales team
Free, no-obligation quotation · takes about 1 minute
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Frequently Asked Questions
What is the difference between a safety valve, a relief valve and a safety relief valve?
In common usage a safety valve opens with a rapid pop action and is used on gas, vapor and steam. A relief valve opens gradually in proportion to overpressure and is used on liquids. A safety relief valve is designed to work in either way depending on the application. Manufacturers' type names vary, so specify the fluid state and the code and let the sizing decide.
When is a balanced bellows safety valve needed instead of a conventional one?
The set pressure of a conventional spring-loaded valve is affected by back pressure at its outlet. If the valve discharges into a flare or closed header where back pressure varies, or built-up back pressure is high, a balanced bellows design cancels that effect and also keeps corrosive discharge fluid away from the spring and guide. Pilot-operated valves are another option for high back pressure.
What is a change-over valve and why is it fitted under safety valves?
A change-over valve is a three-way valve fitted under two safety valves. One safety valve is always connected to the protected equipment while the other is isolated and can be removed for inspection or testing. Because the design never isolates both at once, the plant keeps its overpressure protection without a shutdown. Inlet-side and outlet-side change-over valves can be linked for closed discharge systems.
Are hydraulic pressure relief valves the same as safety valves for vessels?
No. Hydraulic relief valves from makers such as KRACHT and Bosch Rexroth limit the working pressure in an oil hydraulic circuit and protect pumps, cylinders and hoses. They are selected by nominal size, pressure range and mounting pattern. Safety valves for vessels, boilers and process piping are code-stamped devices with a code-approved relieving capacity. One cannot be substituted for the other.
Which documents come with a safety relief valve?
On request we provide the manufacturer's datasheet and the certificates the manufacturer issues for that valve. These typically include the set pressure test certificate, material certificates for the pressure-containing parts, and the code or type approval documentation that applies, such as ASME or PED. Specify the certificates when you ask for the quotation, because they are produced with the valve.
Do you supply safety relief valves in Oman and the other GCC countries?
Yes. Seven Star LLC is based in Muscat and quotes safety relief valves for buyers in Oman, the UAE, Saudi Arabia, Qatar, Kuwait and Bahrain. Buyers in other countries can also send a request. For a quotation, send the set pressure, fluid, relieving temperature, orifice or required capacity and connection sizes through the inquiry form.
Which safety relief valve brands can Seven Star quote?
This category currently lists items from LESER, KRACHT, Anderson Greenwood, Crosby, Bosch Rexroth, Swagelok and Emerson. Other manufacturers can be quoted on request: send the brand and the model or part number, and we will confirm whether we can source it.