Posi-Stop™ - A Superior Union Seal

Caleffi North America, Inc., a leader in state-of-the-art engineered solutions for hydronic and plumbing systems, is pleased to announce an advanced technology named Posi-Stop™ that incorporates an embedded O-ring into a product’s union connection. This advanced design results in a consistent and superior seal over the broad range of conditions encountered in plumbing and hydronic applications, streamlining installation and service.

Take the guesswork out of your connections. When an installer tightens Posi-Stop™union nut an EPDM O-ring seal compresses to a controlled value by way of a positive metal-to-metal stop. For service, you can remove and reinstall a Posi-Stop union without replacing any parts. 

The embedded O-ring provides a reliable seal to liquid and air, allowing contractors to pneumatically test systems with air in order to identify leaks before putting the system into operation.

To identify a product utilizing the Posi-Stop union connection, look for the Posi-Stop name on the product box.