The Porter Models 8310 regulator is an integration of a threadless valve seat and precision glass ball. The unit is used in low flows and provides the dead-end systems with tight flows. Models 8310 and 8311 direct acting, non-relieving pressure regulators come with an inlet fixed with a replaceable sintered stainless-steel cartridge filter. The unit minimizes permeability in stainless steel diaphragms. The regulators undergo a performance test in simulated operating conditions. They are cleaned prior to application in analytical instrument service.