Recently, NIBCO was asked whether or not 2" and 3" press fittings can be crimped in temperatures as low as 10°F.
The short answer? Yes, they can. The NIBCO® Press System® is rated at 200 PSIG over a temperature range of -20°F to 250°F, however the real challenge is testing your system for leaks at such a low temperature.
Testing Your System For Leaks
Before we get into any specifics, let's talk about testing the system for leaks. There are two ways to make sure your system is free of leaks: testing with water or with air. At such a low temperature, you will have problems with the water freezing, so you will probably have to opt for air testing. For more information on testing your system for leaks, view Press Fittings and Valves: How to Detect Leaks.
The EPDM Seal Needs to Relax
With the NIBCO Press System, a watertight joint is formed between the EPDM seal and the crimped fitting or valve providing a permanent connection. However, in freezing temperatures the EPDM o-ring will have a hard time relaxing to create that seal. Think of it like taking something frozen and trying to bend it - the cold will create too much stress for the item to relax enough to be bent.
Get Accurate Testing Results
Before testing the crimp you pressed at a low temperature, you should wait, if possible, until your installation site is at a temperature above freezing, so the EPDM seal will have time to relax and form, giving you the most accurate testing results. It is also important to note that if you do wait and your installation site has a 40°F temperature change or more, you will have varying pressure differences. You may need to account for these pressure differences during your installation.
The NIBCO Press System is rated at 200 PSIG over a temperature range of -20°F to 250°F, meaning the crimp can be made at temperatures as low as -20°F, but for the most accurate results it is best to wait for a more ambient temperature before performing a test to make sure your crimp is leak free. To learn more about the NIBCO Press System, download the quick reference guide!
- Press Fittings and Valves: How to Detect Leaks
- Press Fittings and Valves: Small Diameter Installation
- Press Fittings and Valves: Large Diameter Installation