Nibco KW-900-W-LF Check Valve ...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$3,958.74
Nibco KW-900-W-LF Check Valve - Lead-Free*, Iron, Fire Protection, Wafer Style

Nibco KW-900-W-LF Check Valve - Lead-Free*, Iron, Fire Protection, Wafer Style

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Model: NLM15XM

In Stock (leaves warehouse same day if ordered before 3pm ET)

$3,958.74
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The check valve is wafer style to fit between standard flanges. The twin disc check valve includes renewable bronze discs. Wafer checks may be installed in horizontal positions (or vertical with flow moving up). Please refer to NIBCO technical data sheets, chemical resistance guides and catalogs for engineering and installation information. Choose NIBCO® check valves for the most specified, versatile and economical valve option in commercial, mechanical and industrial applications. NIBCO® check valves are backed by the NIBCO 5-year 125% limited warranty.

  • Valve pressure rating 250 psi/17.2 bar non-shock cold working pressure
  • Spring actuated
  • Renewable discs
  • Rubber seat
  • Double door
  • To be installed between standard Class 125 flanges
  • Wafer connection
  • Listed by Underwriters Laboratories of U.S. and Canada (UL/ULC)
  • FM approved
  • NSF/ANSI/CAN-61 and 372

Twin Disc Check Valves KW900WLF-W920WLF IOM Manual

Manufacturer Resources

Product Specs

All Application(s):
Fire Protection;Lead-Free
All Basic Material:
Cast Iron
Classification:
Inline Lead-Free
End Connection:
Wafer
Product Group:
Valve
Seat Seal Material:
Buna-N Nitrile Rubber
System Use:
Lead Free*
Type of Check Valve:
Inline;Twin Disc
Type of Valve:
Check Valve
Valve End Connection Type:
W -- Wafer
Valve Pressure Rating (CWP):
250 PSI / 17.2 Bar CWP
Product Subgroup:
Valves
Product Type:
Inline Lead-Free
Department:
Plumbing

Nibco NLM15XM – Frequently Asked Questions

1) Can a wafer check valve be installed in a vertical riser, or does it have to be horizontal?
Both work, with one condition on the vertical. The KW-900-W-LF twin disc check can go in horizontal runs, or in a vertical line only where flow is moving up. Flow-down vertical is not an installation position for this valve. The discs are spring actuated, which is what lets it seat in a horizontal position without relying on gravity.
2) Is the Nibco KW-900-W-LF approved for fire sprinkler and standpipe service?
It is Listed by Underwriters Laboratories of the U.S. and Canada (UL/ULC) and FM approved, and Nibco lists fire protection as an application for it. Those two marks are what a fire marshal or an AHJ looks for on a check valve in a sprinkler or standpipe system, so it can be submitted on that basis.
3) Is the Nibco KW-900-W-LF check valve lead-free and OK for potable water?
It carries NSF/ANSI/CAN-61 and 372, which are the drinking water contact and lead content standards, and Nibco designates it lead-free. That matters on a combined domestic and fire service where the check sits on water that eventually reaches fixtures, and on jobs where a plan reviewer requires lead-free certification through the whole service line.
4) What pipe sizes does the Nibco KW-900-W-LF check valve come in?
Eight sizes, 2-1/2, 3, 4, 5, 6, 8, 10 and 12 inch. That covers most fire service mains and standpipe risers. The 5 inch is worth noting because plenty of check valve lines skip it, so if you are matching an existing 5 inch fire main you do not have to bush down.
5) Should I use a twin disc wafer check or a full-body swing check on my fire main?
The twin disc is the short-lay-length option. Two spring-loaded half discs fold back against the flow instead of one large plate swinging through an arc, so the valve takes up very little run between flanges and does not need the extra body length a swing check does. That makes it the one to use in a tight riser or a crowded pump room, and it is why it can be mounted horizontally without gravity assist. A swing check is the alternative where you want a lower pressure drop at low flow or need an accessible bolted cover for in-line inspection. The KW-900-W-LF is the wafer twin disc.
6) Do I need anything besides the valve to install a wafer check between two flanges?
Yes, and it is the part people forget. A wafer valve ships as the body alone: you supply two flange gaskets, one on each face, plus the through bolts or studs and nuts sized for the flange pattern at your pipe size. The KW-900-W-LF has no flanges of its own and no bolt holes, so the flange bolts run past the body. If the run is not already flanged, add the flange adapters to the order too.
7) Can the discs on the Nibco KW-900-W-LF be replaced without pulling the valve out of the line?
The discs are renewable bronze discs, so the sealing elements are a serviceable item rather than a throwaway body. The seat is rubber, specifically Buna-N nitrile. Practically, the valve is clamped between flanges, so getting at the internals means breaking the flange joint and dropping the wafer out; the value of renewable discs is that once it is out you rebuild it instead of buying a new valve.
8) What is the KW-900-W-LF check valve body made of, and will the Buna-N seat handle a glycol antifreeze loop?
Cast iron body with a Buna-N nitrile rubber seat. Buna-N is the standard elastomer for water and glycol service and is not suited to hot oil or strong oxidizers. Cast iron means it is a water and fire protection valve, not a valve for corrosive process fluid. For anything past plain water, check Nibco's chemical resistance guide against the specific fluid before you commit the valve.
How fast can I get the Nibco NLM15XM delivered?
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Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Nibco NLM15XM come with a warranty?
Absolutely. The Nibco NLM15XM is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Nibco NLM15XM?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
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