Thermostatic expansion valves and orifices

Thermostatic valves

One of the most important elements of refrigeration automation whose task is to maintain the required temperature at a constant level is the throttle element, which should regulate the flow so as to maintain a balance between the amount of injected medium and the amount of steam sucked from the exchanger by the compressor. This role in the refrigeration system can be filled by: capillary tube, automatic expansion valve, thermostatic expansion valve, electronic expansion valve, low or high pressure float valve.

The thermostatic valve controls the amount of refrigerant supplied to the evaporator depending on the superheated vapor. In order to accomplish its task, the TZR is equipped with a control element whose sensor (in the form of a metal bulb) mounted at the end of the evaporator measures the actual superheating temperature of the escaping vapors. There are several ways of filling the sensor and hence: steam-liquid (referred to as MOP - Maximum Operating Pressure - fillling); liquid filling; absorbent filling. Depending on the type of filling, different valve operating characteristics are obtained in terms of its sensitivity, inertia, preferred operating temperatures, performance range.

In our offer you will find thermostatic valves with replaceable Danfoss orifice, produced with screwed in or soldered connections in the temperature range from -60 ° C to + 50 ° C and nominal capacity up to a dozen or so kW, and orifice sets with filters whose nominal capacity is determined by: evaporating temperature te = + 5 ° C for the range N (-40 - 10 ° C) and te = -30 ° C for the range B (-60 - -20 ° C) Condensing temperature tc = + 32 ° C Medium temperature before the valve tl = + 28 ° C In order to ensure correct functioning of the expansion valve, it is necessary to strictly observe the assembly rules, especially regarding the place and method of mounting of the sensor, the method of assembly of the pressure equalizing pipe and also the regimes during soldering (protecting the valve against overheating during this operation).