refrigeration valves : RFF, hand-regulating valves

<body bgcolor="#FFFFFF"> Hand-regulating valve, straight with handwheel or with cap from DN 10 up to DN 40 (stainless steel range from DN 10 up to DN 25) RFF hand-regulating valves are constructed from low temperature carbon steel with stainless steel spindles sealed by two O-rings with a special oil filled groove which provides a complete gas tight seal. RFF hand-regulating valves can be supplied with a material certificate for body and bonnet which guarantees the impact strength at -50°C. The O-rings can be replaced when the spindle is back-seated fully. Maintenance of the O-rings can be carried out without shutting down the plant. Regulating is carried out by restricting the passage by a conical seal (cone), and with the new models shut-off is obtained by PTFE to steel contact. Hand regulating valves can be identified by a series of two grooves machined into the vertical bonnet surface. They are painted mauve in colour. Hand-regulating valves have a normal maximum flow-rate which depends on their nominal diameters, but they can be fitted with special cones to give a higher-than-standard flow-rate. The new Hand Regulating Valves can be described as straight through. Angle versions are possible for sizes DN 15, 25 and 40mm only. The angle valve dimensions are identical to the angle Shut Off By using valves fitted with caps on installations using odourless refrigerant extra security is ensured. Gas refrigerant is contained under the cap which is manufactured with small hole drilled under the gasket. When the cap is unscrewed, any build-up of refrigerant gas inside the cap will escape through this hole and can be heard as a whistling noise. This is an indication that the O-rings in the gland nut have been damaged or are in poor condition. All hand-regulating valves can be fitted with handwheels or caps. Branch connections : for butt welding, "S" class (ASTM pipe schedule standard) for butt welding, "M" class (Din 2448) for brazing, "B" class for socket welding, "K" class (angle weld instead of full penetration weld) This range of valves have the same design as the steel range except : Available from DN 10 up to DN 25. Stainless steel shell in X4CrNi 18-10 (1.4301) EN10088-3. Cap in aluminium or handwheel in bakelite. Connection : thickness 2mm for stainless steel pipe, "H" class. </body>