Solenoid valves type EVSA 25 50

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1 Solenoid valves type EVSA Introduction EVSA is an assisted lift, servo operated solenoid valve. EVSA 25, 35 and 50 are for use in suction lines - EVSA 25 in liquid and return lines too - in refrigerating and air conditioning systems where low pressure drops are required. Approvals DSRK, Deutsche Schiffs-Revision und -Klassifikation, Germany W FIMKO, Finland P Polski Rejestr Statków, Poland EVSA can also be supplied in materials GGG 40.3 according to TAA (Sicherheitstechnische Anforderung an Kälteanlagen mit Ammoniak). Please contact Danfoss. Technical data Refrigerants R 717 (NH 3 ), R 22, R 134a, R 404A, R 12, R 502 etc. Ambient temperature C Enclosure IP 67 to IEC 529 Opening differential pressure Max. p bar Temperature working pressure Max. (= MOPD) of medium k v value 1 ) PB Min. Liquid Gas C bar m 3 /h EVSA EVSA ) ) EVSA ) The k v value is the water flow in m 3 /h at a pressure drop in the valve of 1 bar, ρ = 1000 kg/m 3. 2 ) Max. opening differential pressure with direct current: p = 15 bar. Rated capacity 1 ) kw Liquid Suction vapour R 717 R 22 R 134a R 404A R 12 R 502 R 717 R 22 R 134a R 404A R 12 R 502 EVSA EVSA EVSA ) Rated liquid and suction vapour capacity is based on evaporating temperature t e = 10 C, liquid temperature ahead of valve t l = +25 C, and pressure drop across valve p = 0.15 bar. Catalogue RK.00.H Page 154

2 Ordering Complete valves Valve body with flanges, flange gaskets, bolts and coil Connection 1 ) Code no. 2 ) a.c. or d.c. EVSA 25 1 in. weld 32Z /8 in. solder 32Z0202 EVSA /2 in. weld 32Z /8 in. solder 32Z0205 EVSA 50 2 in. weld 32Z /8 in. solder 32Z ) All valves can be supplied with mm version solder connection. 2 ) Please specify code no., voltage and frequency. Separate coils (spare parts) Example EVSA 25 with 1 1/8 in. solder flanges, 220 V, 50 Hz, code no. 32Z0202, 220 V, 50 Hz (or expressed with appendix no.: 32Z ) Separate coils for EVSA Voltage Valve type 1 ) 2 ) Frequency Code no. Appendix no. 3 ) V Hz Alternating current a.c. MOPD = 17.5 bar Z Z Z Z Z Z EVSA 25, 35 and Z Z /60 32Z /60 32Z Z Z Z Power consumption Holding: 22 W, 60 VA Inrush: 140 VA Direct current d.c. MOPD = 15 bar 48 32Z EVSA 25, 35 and Z W Z ) Permissible voltage variation: ±10%. 2 ) Coils with other voltages can be supplied to special order. 3 ) Appendix no. clearly indicates type of current, voltage and frequency. Catalogue RK.00.H Page 155

3 Capacity Capacities are based on liquid temperature t l = +25 C ahead of valve, evaporating temperature t e = 10 C, and superheat 0 K. Liquid capacity Q e kw Liquid capacity Q e kw at pressure drop across valve p bar R 717 (NH 3 ) EVSA EVSA R 22 R 134a EVSA R 404A EVSA Correction factors When sizing valves, the plant capacity must be multiplied by a correction factor depending on liquid temperature t l ahead of valve / evaporator. When the corrected capacity is known, the selection can be made from the table. t l C R 717 (NH 3 ) R 22, R 134a R 404A Catalogue RK.00.H Page 156

4 Capacity (continued) Capacities are based on liquid temperature t l = +25 C ahead of evaporator. The table values refer to the evaporator capacity and are given as a function of evaporating temperature t e and pressure drop p across valve. Capacities are based on dry, saturated vapour ahead of valve. During operation with superheated vapour ahead of valve, the capacities are reduced by 4% for each 10 K superheat. Suction vapour capacity Q e kw Pressure drop across valve p bar Suction vapour capacity Q e kw at evaporating temperature t e C R 717 (NH 3 ) EVSA EVSA EVSA R EVSA EVSA EVSA R 134a EVSA EVSA EVSA R 404A EVSA EVSA EVSA Correction factors When sizing valves, the evaporator capacity must be multiplied by a correction factor depending on liquid temperature t l ahead of expansion valve. When the corrected capacity is known, the selection can be made from the table. t l C R 717 (NH 3 ) R 22, R 134a R 404A Catalogue RK.00.H Page 157

5 Design Function EVSA is a forced servo operated solenoid valve. EVSA 25, 35 and 50 are for use in suction lines (the EVSA 25 in liquid and return lines too). Forced servo operation differs from servo operation in that in a forced servo operated valve the coil helps to lift the servo piston (80) and keep it lifted so that the pressure drop in the open valve is the least possible. These types of valves therefore require no differential pressure to keep them open. 4. Coil 16. Armature 18. Pilot valve plate 29. Pilot orifice 53. Spindle for manual opening 73. Equalization hole 80. Servo piston 83. Main seat The EVSA has a built-in strainer and spindle (53) for manual opening. Dimensions and weights H 2 H 4 L L 1 B Weight mm mm mm mm mm kg EVSA EVSA EVSA Catalogue RK.00.H Page 158