The SharkBite Female Center Slip Tee is the perfect fitting to add an expansion tank for your water heater and other similar applications. The slip tee allows for the fitting to be connected to the pipe and, using the Disconnect Clips, slipped back onto the other end of the pipe without the need for additional pipe or tubing. The FNPT branch is threaded so that you can directly connect the expansion tank after installing the tee to the line. This product is rated to 200 F and 200 psi, and can be easily rotated on the pipe after installation making it much easier to work in tight spaces. ASSE 1061. CSA B125.3. NSF 372. NSF/ANSI 61.