B1796632 – PISTON NUT & TEFLON SEAL

This piston nut and Teflon seal kit secures the flowrater piston inside the refrigerant line on Goodman and Amana systems. If you’re replacing a piston or have a refrigerant leak at the piston connection, you’ll likely need a new nut and seal to get a tight, leak-free fit.

Specs: Piston nut with Teflon seal, OEM assembly

Replaces: B1796632

Fits: Goodman and Amana condensers and heat pumps that use a piston metering device

In stock at Open To Public HVAC Parts in Dallas. We test parts at the counter before you buy. Call or text (214) 340-9421.

Specs

• TypePiston Teflon seal + brass nut
• OEM CompatibilityUniversal

Cross-reference numbers

This part replaces the following OEM and aftermarket numbers:

• B1796632

Not sure if your number matches? Call (214) 340-9421 or bring the old part in — bench-testing is free.

Fits these models

• Replacement Teflon seal + brass nut for flowrater piston installations
• Use a NEW seal every time the piston is removed; never reuse the old one

What does .065 mean on a flowrater piston?

.065 inches is the orifice diameter. Smaller orifice = lower refrigerant flow = sized for smaller capacity or higher-pressure refrigerant. Match to your system's data plate spec.

Why does the same orifice fit different tonnages?

Because R-410A operates at higher pressures than R-22, a smaller orifice meters MORE refrigerant on R-410A than on R-22. So a .065 piston might serve a 2.5-ton R-410A system AND a 2.5-ton R-22 system — but you need to verify on your equipment's manual.

How do I install a flowrater piston?

1. Remove the old piston (often using a piston removal tool that grips the inner orifice). 2. Apply a NEW Teflon seal (don't reuse the old one). 3. Insert the new piston in the correct direction (arrow / flow indicator faces the evaporator distributor). 4. Torque the brass nut to manufacturer spec.

Can I use a piston instead of a TXV?

On some equipment, yes — but the system loses the ability to maintain proper superheat across changing conditions. Fixed-orifice pistons are simpler but less efficient. Check your equipment's installation manual for piston-vs-TXV compatibility.