Direct answer · Updated 25 October 2026
Who manufactures non-slam check valves in India?
Supreme Valves India (Ahmedabad) supplies non-slam check valves: nozzle (axial-flow), spring-loaded silent check and spring-assisted dual plate designs, 2" and above, ASME Class 150 to 600 and PN10 to PN40, in WCB, SS316, LCC, ductile iron, duplex and NAB. They close before flow reverses, preventing check valve slam and water hammer on pump discharge lines. Offers include API 598 test reports and EN 10204 3.1 certificates.
Request a quotation · +91 97732 78770 · info@supremevalves.in
Non-Slam Check Valve Manufacturer in India
Spring-assisted check valves that close before flow reverses, eliminating slam and water hammer on pump discharge, parallel pump headers and pipelines.
What is a non-slam check valve?
A non-slam check valve (also called a silent, nozzle or axial-flow check valve) closes under spring force with a very short disc stroke, so the disc is already on the seat when the flow stops. A conventional swing check valve has a heavy disc that swings through a long arc and is still open when the flow reverses; it then slams shut against the reverse flow, causing water hammer, pressure surges and damage to pipes, supports and pumps.
The key performance measure is reverse velocity at closure: the lower it is, the smaller the surge. Non-slam designs reach full closure at very low reverse velocity, which is why they are specified on pump discharge lines, parallel pump headers and long pipelines.
Non-slam check valve types we supply
Specification range
How to size a non-slam check valve (and avoid chatter)
Size a non-slam check valve by flow velocity, not only by line size. If the valve is oversized, the disc does not open fully, it chatters on the spring and the seats and guide wear quickly. If it is undersized, pressure drop rises. Send us the minimum, normal and maximum flow, the fluid and the pump arrangement and we check the valve against its full-open velocity before quoting.
- Water service: the valve should be fully open at normal flow; typical full-open velocities are around 1.5–2.5 m/s depending on design and spring.
- Parallel pumps: specify non-slam checks on each pump discharge; the stopping pump sees very fast flow reversal.
- Vertical lines: state flow direction (up or down) so the spring can be selected correctly.
- Seawater: specify NAB or duplex body with Monel or Inconel springs.
Industries and export markets
Water supply and treatment pump stations, desalination, fire water, cooling water, district cooling, oil and gas pipelines, refinery and petrochemical pump discharge, and marine seawater systems. Supply across India and export to the UAE, Saudi Arabia, Oman, Qatar, Kuwait and Africa with EN 10204 3.1 material certificates and API 598 test reports.
What to send with your enquiry
- Size, pressure class and quantity
- Fluid, temperature, and minimum / normal / maximum flow
- Body and trim material, seat type (metal or resilient)
- End connection: flanged RF, wafer, PN flanges
- Installation: horizontal, vertical flow up or vertical flow down
- Design standard, coating and inspection requirements
Send the line list or datasheet to info@supremevalves.in or use the quote builder. Technical clarifications and a priced offer follow within one working day for standard items.
Related products and guides
Non-slam check valve product
Product page with specifications and datasheet.
Silent check valve, nozzle type
Axial-flow nozzle check valve.
Dual plate check valve manufacturer
API 594 wafer and lug dual plate checks.
Swing check vs dual plate check
Selection comparison.
Non-slam checks for pump stations
Engineering guide for pump discharge.
Silent check valve RFQ, FBE coated
WCB, SS316L internals, EPDM seals.
NAB seawater valves
Non-slam checks for seawater and desalination.
Check valve manufacturer India
Swing, lift, dual plate and non-slam range.
Frequently asked questions
What is the difference between a non-slam check valve and a swing check valve?
A swing check valve has a heavy disc that closes only after flow reverses, so it slams. A non-slam check valve uses a spring and short disc stroke to close as the flow decelerates, before reversal, which prevents slam and water hammer.
Is a nozzle check valve the same as a non-slam check valve?
A nozzle (axial-flow) check valve is one type of non-slam check valve. Silent check valves and spring-loaded dual plate check valves are other non-slam designs.
Can a non-slam check valve be installed vertically?
Yes, in vertical flow-up lines, and in flow-down lines with a suitable spring. State the orientation with your enquiry so the spring is selected correctly.
Why does my check valve chatter?
Chatter usually means the valve is oversized for the flow, so the disc never opens fully. A non-slam check valve should be sized so it is fully open at normal flow.
Which standards apply to non-slam check valves?
Pipeline nozzle checks are generally built to API 6D, dual plate checks to API 594, with pressure-temperature ratings to ASME B16.34 and testing to API 598.
Do you export non-slam check valves?
Yes, to the Middle East, Africa and Asia with EN 10204 3.1 certificates, API 598 test reports and third-party inspection when required.
About this page: Written by the Supreme Valves India engineering team, Ahmedabad (supplying industrial valves since 1986). Last reviewed 25 October 2026. Figures are typical values for selection; the governing values are those in the referenced standard and on the approved datasheet for each order. Entity facts: Supreme Valves brand facts.
Pump discharge or water hammer problem?
Send size, pressure rating, material, end connection and service. Engineering response within one working day.