The enhanced Circle Seal XVH range of excess flow valves from Circor provides increased versatility, application flexibility and reliability in automatically preventing uncontrolled release of system fluid by closing leak-tight when flow exceeds a predetermined rate. These quick-acting flow switches are also said to ensure a safer working environment at lower cost and with maintenance requirements reduced to a minimum. Available in both automatic and manual reset versions, they have a working range of 0 to 6000 psig. A wide choice of O-ring, seal and body materials enables the valves to be used with any liquid or gas service over a large temperature range. The spring-loaded poppet may be mounted in any orientation and a large range of end connection options allow assembly in all systems. Manual valves ensure zero leakage until individually reset. The bleed valves on automatic models have an ‘anti-clog’ wire that increases reliability by preventing a build-up of system fluid in the bleed port. Coloured ring bands on all models give instant visual indication of valve type, trip range and seal material.