Description The OPW SBC-2150 FlexWorks Swivel Bolt-On Coupling features a double wall design that eliminates the need to trim back the secondary jacket. The need for rubber test boots is eliminated. Permanent access to the pipes interstice allows for future integrity testing or continuous interstitial monitoring. Swivel Bolt-On Couplings have an integral interstitial fluid path and a threaded access port located directly on the coupling collar. This state of the art method of connection is a cost effective solution that allows rapid system integrity testing as well as interstitial monitoring capability, at installation and in the future to accommodate new monitoring regulations.