Do you have the white Teflon flat washer / gaskets for the older style union tank tees?

Yes, although we do not use the term "TEFLON" as it is an infringement on a registered trademark of Dupont.  For this reason, we refer to the washers as P.T.F.E. which stands for actual material name "Polytetrafluoroethylene".

The part numbers are 07PT-TW-10 (1” tees) and 07PT-TW-12 (1-1/4” tees), the transition from the “P.T.F.E. WASHERS”  to the current “O-RING” seal occurred back in 2014. It was a running change under the same part number(s) has caused some confusion.

 07PT-TW-10        P.T.F.E. WASHER FOR ALL 1" UNION TANK TEES

Used in older model UNION TEES prior to change to an O-RING seal in July of 2014

Part No’s: 07ST-25S-2U, 07ST-8-2U, 07ST-25-2U & 07ST-14X1-2U

07PT-TW-12        P.T.F.E. WASHER FOR ALL 1-1/4" UNION TANK TEES

Used in older model UNION TEES prior to change to an O-RING seal in July of 2014

Part No’s: 07ST-13S-2U & 07ST-13-2U

The washer / gasket dimensions are detailed below.

Why the design change from the P.T.F.E. Gasket to O-Ring Union Seal was made.

While the durable P.T.F.E. (Polytetrafluoroethylene) washer provided an excellent seal, the change to the O-Ring seal was made for the two reasons below.

#1 - Significant changes in installation practices from rigid piping to PEX piping from the tee to the household plumbing and the use of poly pipe and / or braided hose from the well / submersible pump result in the tank tee head going out of alignment due to the slippery characteristics of P.T.F.E. gasket, the tank tees heads tended to swivel if the line connection piping is not properly supported. The O-Ring seal provides a gripping action which eliminates any swivelling at the union holding the tank tee head in perfect alignment.

#2 - The flat washer type PTFE gaskets were more likely to fallout of the union nut and get lost. The new O-Ring designs have the O-ring secured, either in a precision machined groove (Stainless Steel Tank Tees) or over the casting (NL Brass Tank Tees) these systems reduce the risk of the seal falling out.