American Standard Flash Shower...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$132.39
$84.79
American Standard Flash Shower Rough-In Valve With PEX Inlets/Universal Outlets With Screwdriver Stops for Cold Expansion System - AMS-RU108SS

American Standard Flash Shower Rough-In Valve With PEX Inlets/Universal Outlets With Screwdriver Stops for Cold Expansion System - AMS-RU108SS

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Model: RU108SS
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$132.39
$84.79
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Flash Shower Rough-In Valve With PEX Inlets/Universal Outlets With Screwdriver Stops for Cold Expansion System
  • Flush Plug: Eliminates the need to remove cartridge during installation and allows installer to flush the lines without cross flow. Can be tested using flush plug with air (200 psi) or water (300 psi).
  • Stainless Steel Retaining Ring with Flats: Secures test cap/ cartridge in place and eliminates need for screws. Flats make it simple to loosen ring for quick, easy insertion/removal of test cap/cartridge.
  • Flat Back: Allows valve to be mounted flush against cross brace for easy and solid installation
  • PEX Connections: Fast and easy installation without adaptors reducing leak points.
  • Cast DZR Brass Valve Body: Resists corrosion due to high chloride and pH levels in water.
  • Back-to-Back Capability: Hot and cold can be reversed quickly and easily.
  • Exclusive Plaster Guard: Plaster guard is designed to protect valve and act as a guide during installation. It can serve as mounting support for thin-wall installations.
  • Wide Rough-in Range: From 1-3/4" to 2-3/4" from finished wall to the back of the valve.
  • 1/2" PEX cold expansion inlets/Universal outlets (ASTM F1960)
  • Includes Scredriver Stops for easy servicing at the valve;Cartridge Ships with Trim

Manufacturer Resources

Product Specs

Product Group:
Washroom/Bath
Product Subgroup:
Parts and Accessories
Product Type:
Rough In Valve
Department:
Plumbing
Parts and Accessories Type:
Rough-In Kit
Application:
Toilet

American Standard RU108SS – Frequently Asked Questions

1) Does the American Standard RU108SS shower rough-in valve connect directly to PEX, or do I need adapters?
It takes 1/2 inch PEX cold expansion inlets directly, no adapters. The inlets are built for the ASTM F1960 cold expansion system, so you expand the ring and tubing and slide it on. Fewer transitions means fewer leak points behind the wall. Outlets are universal.
2) How deep can this rough-in valve sit behind the finished wall?
The Flash rough-in valve has a range of 1-3/4 inches to 2-3/4 inches measured from the finished wall to the back of the valve. That inch of play covers most framing and wall buildups, including tile over backer. The plaster guard doubles as a depth guide during setting, and on thin-wall installs it can act as mounting support.
3) Does the American Standard RU108SS come with the cartridge and trim?
No. The valve body ships with a flush plug, plaster guard, stainless retaining ring and integral screwdriver stops. The cartridge comes with the trim kit, which is ordered separately, so plan on buying a Flash trim package to finish the shower.
4) Can I pressure test the shower lines before the cartridge goes in?
Yes, that is what the flush plug is for. You leave the cartridge out entirely, flush the lines without cross flow between hot and cold, and test through the flush plug at up to 200 psi with air or 300 psi with water. The stainless retaining ring has flats on it so the test cap backs off by hand tool instead of screws when you are ready to drop the cartridge in.
5) Can the shower be isolated for service without shutting down the building water?
Yes. Screwdriver stops are built into this rough-in valve, so a maintenance tech pulls the trim escutcheon, closes both stops with a flat blade, and services or swaps the cartridge without killing the riser. For property managers and multi-family MRO that is the difference between a one-unit shutoff and a whole-stack notice.
6) Is the RU108SS the crimp PEX version or the expansion version?
Cold expansion. Model RU108SS uses 1/2 inch PEX-a cold expansion inlets built to ASTM F1960, the system where the tube and ring are expanded with a tool and shrink back onto the fitting. If your crew runs crimp or clamp rings on PEX-b, this is not the inlet style you want.
7) I plumbed the hot and cold backwards on this valve. Do I have to re-pipe it?
No. The Flash rough-in valve has back-to-back capability, so hot and cold can be reversed at the valve quickly rather than tearing out and re-running supply lines. That is the usual fix on back-to-back bathroom layouts where the supplies land on the opposite sides.
8) Will this valve hold up in aggressive water with high chloride?
The body is cast DZR (dezincification resistant) brass, chosen to resist corrosion where chloride and pH levels in the water run high. That is the material spec to look for on coastal and high-TDS municipal supplies where standard brass suffers.
9) How does the American Standard Flash valve mount to the cross brace?
It has a flat back, so it sits flush against a 2x brace between the studs instead of rocking on a curved casting. Set it flat, fasten the brace, and use the plaster guard to set your finished wall depth within the 1-3/4 to 2-3/4 inch range.
How fast can I get the American Standard RU108SS delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
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 American Standard RU108SS come with a warranty?
Absolutely. The American Standard RU108SS 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 American Standard RU108SS?
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
Why buy the American Standard RU108SS from ZenSupply?
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