Description
Connection
1/8″ MNPT × 1/4″ QC
Tube Side
Push-to-Connect
A straight adapter that connects standard 1/4″ OD RO tubing to a 1/8″ MNPT threaded port — the fitting for RO membrane housings and components that use the smaller 1/8″ thread. Push-to-connect tube side, threaded port side.
What it does
This straight adapter connects standard 1/4″ OD tubing to a 1/8″ Male NPT threaded port. The tube side is push-to-connect — just push the tubing in for a tight, leak-resistant grip. The threaded side is a standard 1/8″ MNPT connection, sealed with PTFE (Teflon) tape or an approved thread sealant.
The 1/8″ thread is the smaller port size found on many RO membrane housings and filtration components — so this is the adapter you reach for when your port is 1/8″ rather than the more common 1/4″. Made from durable, food-grade material for reliable sealing in residential and commercial water-filtration setups.
Key benefits
- ✓1/8″ MNPT × 1/4″ OD — adapts standard 1/4″ tubing to a smaller 1/8″ port
- ✓For 1/8″ ports — common on RO membrane housings and filtration components
- ✓Push-to-connect tube side — tool-free; push the tube in, press the collet to release
- ✓Reusable — tubing releases and reconnects by pressing the collet
- ✓Food-grade material, suitable for potable water applications
- ✓Automatic quantity discounts — keep spares in the parts drawer
Specifications
| Thread (port side) |
1/8″ MNPT (male) |
| Tubing (tube side) |
1/4″ OD quick-connect |
| Orientation |
Straight |
| Thread seal |
PTFE (Teflon) tape or thread sealant |
| Connection |
Push-to-connect, tube side (tool-free) |
| Use |
Cold / potable water |
| Sold as |
Single unit |
| Dimensions |
1 × 1 × 0.5 in |
| Weight |
0.05 lbs |
| Brand |
MyWaterClub |
| Brand |
MyWaterClub |
| SKU |
FT-ST-18-QC14 |
Compatibility
✓ Works with
- Any 1/8″ MNPT (male-threaded) port — common on RO membrane housings & components
- Standard 1/4″ OD RO tubing (push-to-connect)
- RO systems, water filters, ice makers, fridges & beverage systems
× Not for
- 1/4″ threaded ports — use the 1/4″ MNPT fitting for those
- 3/8″ OD tubing (this is for 1/4″ OD tube)
- Hot-water or high-pressure lines — cold / potable water only
Often used with
1/4″ RO Tubing
The tube this adapter connects — white or clear
View tubing →
Countertop RO Systems
Systems that use 1/4″ connections
View systems →
RO Parts & Accessories
Housings, clips, adapters & more
Browse parts →
RO Replacement Sets
Refresh your filters on schedule
View sets →
Installer & plumber bulk pricing
Buying these fittings by the case?
Contact us for case-quantity installer pricing.
Good to know before you buy
- Wrap the 1/8″ thread with PTFE (Teflon) tape (2–3 turns) or apply an approved thread sealant before installing. Unlike push-fit-only fittings, this threaded side needs tape to seal. Hand-tighten — do not over-torque, which can crack the plastic.
- Push the tubing fully into the quick-connect side until it seats. A firm push past the initial resistance locks it in. Give the tube a gentle tug to confirm it’s held.
- To remove tubing: press and hold the collet ring flat against the fitting, then pull the tube straight out.
- Confirm your port is 1/8″ MNPT and your tubing is 1/4″ OD — the two most common mismatches on this adapter.
- For cold / potable water only — not for hot-water or high-pressure lines.
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