Forbes Marshall is the supplier of Thermostatic Instrument Tracer Steam Trap. Forbes Marshall is an ISO 9001 certified company. The Thermostatic Instrument Tracer Steam Trap MST 21is a maintainable balanced pressure trap designed for small condensate loads, usually associated with instrument tracing applications. The Thermostatic Instrument Tracer Steam Trap is manufactured in stainless steel. These Thermostatic Instrument Tracer Steam Traps are corrosion resistant and easily maintainable.