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Foster FHS4M4B-103, 1/2" Snap-Tite H Interchange Coupler x 1/2" Male NPT, FH Series, EPDM Seal, Brass

Foster 12FS-101, 1/8" Straight-Thru Coupler x 1/8" Female NPT, FST Series, Viton Seal, Brass

by Foster
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$ 13.69
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$ 13.69
$ 10.99
$ 10.99 - $ 10.99
$ 10.99

Maximum-flow connections for air, fluid, and vacuum lines. The Foster 12FS-101 is a brass 1/8" coupler from the FST Straight-Thru Series - with NO valve in either half, so the coupling flows as freely as the pipe itself. Standard industrial interchange, rated to 2500 PSI.

Specifications

  • Brand: Foster
  • Series: FST (Straight-Thru, Industrial Interchange)
  • Part Number: 12FS-101
  • Interchange: 1/8" Standard Industrial
  • Body: 1/8" Coupler
  • Thread: 1/8" Female NPT, FPT
  • Type: Straight-Thru - NO valve in socket or plug (full flow)
  • Operation: Manual sleeve (retract to connect and disconnect)
  • Flow: Inside diameter same as nominal pipe - maximum flow
  • Material: Brass
  • Seal: Viton
  • Max Working Pressure: 2500 PSI
  • Vacuum Service: 27 in. Hg maximum
  • Temperature Range: -40F to +250F
  • Standard: ANSI/B93.2, 4:1 safety factor
  • Quantity: 1pc
  • Origin: Made in USA

Why this coupler

  • Straight-thru, no valve — which means unrestricted full flow with minimal pressure drop, ideal for air, fluid transfer, and vacuum.
  • Same ID as nominal pipe — which means the coupling does not choke your line, maximizing flow and efficiency.
  • Standard industrial interchange — which means it couples with the most widely used industrial coupler design.
  • Brass construction — which means corrosion resistance for water, air, and many fluids.
  • Viton (FKM) seal — which means compatibility with a wide range of fuels, oils, and chemicals at high temperature.

Frequently asked questions

What does straight-thru mean?
There is no shut-off valve in either the socket or the plug, so the coupling flows as freely as the pipe — maximum flow, minimal pressure drop. Note: lines do not self-seal on disconnect.

What does this connect to?
Standard industrial interchange — only same-size FST sockets and plugs couple together.

What pressure is it rated for?
Rated to 2500 PSI (brass, 1/8"), per ANSI/B93.2, 4:1 safety factor.

Ideal for high-flow air, fluid transfer, and vacuum lines where shut-off is not needed. Pair this coupler with a matching 1/8" FST plug.

Why buy from hpcouplers: Foster quality, responsive US-based support, accurate specs, fast shipping.