The MECH pressure relief valve flanged blue, model SK730X, sizes 2″ – 12″ (DN50 – DN300), working pressure PN25. It opens automatically to discharge excess pressure and protect the network and equipment. This guide explains what it does and how it works, related models, technical data, the critical point in selection and installation, and common mistakes. For more, read the guide pressure reducing vs relief valves.
At a glance
- A pressure relief valve stays closed in normal operation and opens when pressure exceeds its set value, discharging water until pressure falls, then closes.
- Sizes 2″ – 12″ (DN50 – DN300).
- Working pressure PN25.
- Connection: Flange BS EN 1092-2.
- Operating temperature: 0 – 80 °C.
Pressure relief valve: what it does and how it works
A pressure relief valve stays closed in normal operation and opens when pressure exceeds its set value, discharging water until pressure falls, then closes.
It is used on pump discharges and in networks exposed to pressure rise and water hammer.
Technical data
| Item | Specification |
|---|---|
| Design standard | CJ/T 219, CJ/T 256, JB/T 10674 |
| Connection ends | Flange BS EN 1092-2 |
| Working pressure | PN25 |
| Temperature range | 0 – 80 °C |
| Coating | FBE — ANSI/AWWA C550 |
| Sizes | 2″ – 12″ (DN50 – DN300) |
Dimensions for every size are in the size table at the top of the page.
Setting and discharge
Set the opening pressure above normal working pressure and below the equipment limit, and pipe the discharge to a safe place that can take the flow.
Caution
Do not fit an isolating valve that could cut the relief valve off from the system in service unless the design allows it.
Installation steps
- Install on the line to be protected with the arrow in the direction of flow.
- Pipe the discharge to a safe place.
- Set and test the opening pressure.
- Inspect it periodically.
Common mistakes
- Setting it too close to working pressure so it opens often.
- Unsafe or undersized discharge.
- No periodic testing.
Files and ordering
On this page: Product datasheet, MECH Water Valves Catalogue, Material Safety Data Sheet (MSDS). Add the product to your request list with size and quantity and we send a quotation, or build a submittal PDF for the consultant. Fu-Mech is the exclusive MECH agent in Saudi Arabia.
Frequently asked questions
Where is it installed?
On pump discharges and in networks exposed to pressure rise.
How is it different from a reducing valve?
A relief valve only opens above its limit; a reducing valve controls pressure continuously. See pressure reducing vs relief valves.
What is the working pressure of model SK730X?
PN25 per the product data. The pressure for each size or listed model is in the size table and datasheet.
What end connection does it have?
Flange BS EN 1092-2. Choose the connection that matches the adjacent pipe and fittings.
References
- BS EN 1092-2 — Flanges and their joints — Cast iron flanges, PN designated
- AWWA C550 — Protective Interior Coatings for Valves and Hydrants
- MECH catalogue — Product datasheet
This guide is general information to help with selection. Figures come from the product data on this page and the MECH catalogue; final design is by the project’s approved designer to the applicable standards and the project specification.
