Sporlan 904073 HGBE-8-75/150, 7/8" X 7/8" ODF Solder Discharge Bypass Valve

Sporlan 904073 (HGBE-8-75/150) discharge bypass valve, 7/8 inch x 7/8 inch ODF (solder) connections. Sporlan is the Parker Hannifin refrigeration controls brand and is the industry standard for commercial refrigeration valves, TXVs, solenoid valves, and filter driers. Discharge bypass valves modulate hot gas from the compressor discharge into the evaporator inlet to maintain stable suction pressure at low load. Applications include commercial refrigeration racks, supermarket refrigeration, low-load operation of large compressors, and any system where capacity modulation without cycling the compressor is required. New condition. New surplus, available from King Surplus inventory in Del Rio, Texas.

REFRIGERANT: this is a pressure-regulating valve, so it works with the common CFC, HCFC and HFC refrigerants but NOT with ammonia. Sporlan publishes capacity tables for this family on R-22, R-134a, R-401A, R-402A, R-404A, R-407C and R-507. R-410A is NOT in the published capacity tables, so confirm with us before applying this valve to R-410A. What actually has to match your refrigerant is the ADJUSTMENT RANGE: the valve setting is in psig, and the psig you need is the saturation pressure of YOUR refrigerant at the minimum evaporating temperature you want to hold. The same 75 to 150 psig range lands at completely different evaporator temperatures on R-22 than on R-404A. Check the range against a pressure-temperature chart for your refrigerant before ordering. Manufacturer: Sporlan Division, Parker Hannifin Corporation, Washington, Missouri, USA Model: HGBE-8-75/150 Sporlan part number: 904073 Type: pilot operated discharge bypass valve, also called a hot gas bypass valve or DBV What the designation means: HGB for hot gas bypass, E for externally equalized, 8 for valve size, 75/150 for the adjustment range in psi, then the connections. NOTE ON THE MISSING S PREFIX: Sporlan's SHGB(E) models carry a solenoid stop feature, meaning de-energizing the coil forces the valve fully closed so no discharge gas is bypassed. This valve has NO S prefix and therefore NO solenoid stop. It modulates on suction pressure only and cannot be commanded shut electrically. If your system runs a pump down cycle you will need a separate hot gas solenoid valve in the bypass line. Adjustment range: 75 to 150 psig. Sporlan's standard SHGB(E) range is 0 to 100 psig with a 69 psig factory setting, so 75/150 is a non-standard range, typically an OEM or special-order build. How to adjust: turn the adjustment screw on the pilot valve. Clockwise raises the setting, counterclockwise lowers it. Setting the valve requires varying the system load, since the load has to be reduced far enough for the valve to control. External equalizer: 1/4 in SAE. The E model requires a FIELD INSTALLED external equalizer line running from the suction line to the pilot valve. Without it the valve will not sense the correct control pressure. Why externally equalized: the compressor suction pressure is the control pressure. Where there is appreciable pressure differential between valve outlet and compressor suction, an internally equalized valve sees a false control pressure when it opens and closes itself. Sporlan recommends the externally equalized version in all cases. CONNECTIONS: 7/8 in ODF x 7/8 in ODF solder. Sporlan also builds this size with 1-1/8 in ODF. Body material: brass. Seating: synthetic to metal. For reference, Sporlan's UL and ULC listing on the solenoid-equipped SHGB(E)-8 covers a maximum working pressure of 450 psig, MOPD of 300 psi, maximum fluid temperature 240 F (116 C) and maximum ambient 120 F (49 C). Read the rating off this valve's own nameplate rather than assuming it matches. How it operates: the main piston is controlled by a pilot valve. Suction pressure acts as a closing force on the pilot and is opposed by the adjustment spring. High pressure gas bleeds into the chamber above the main piston through a restrictor. As suction pressure falls below the pilot setting, the pilot port opens, bleeds that chamber down faster than it fills, and inlet pressure pushes the piston up to modulate the valve open. HOW TO SIZE IT, five inputs: refrigerant; minimum allowable evaporating temperature at reduced load; compressor capacity in tons at that evaporating temperature; minimum evaporator load in tons; and condensing temperature when minimum load exists. The valve has to handle the difference between compressor capacity and minimum evaporator load. If the system must hold to zero load, the requirement is simply the full compressor capacity at the minimum evaporating temperature. Capacity rating basis: capacities assume a 6 F (3.3 K) evaporator temperature change from closed position to rated opening, which Sporlan calls nominal. If you can tolerate an 8 F change the valve opens further and capacity rises by a factor of about 1.15. Minimum condensing temperature: 80 F (27 C) is the lowest Sporlan considers acceptable for satisfactory operation, which is why hot gas bypass on air cooled systems requires head pressure control. Normally when hot gas bypass is used for capacity control the outdoor ambient has fallen below 70 F (21 C). Typical evaporating temperature targets: most air conditioning systems hold a minimum of 20 F to 25 F (-7 to -4 C). Where air velocity across the coil is much reduced, use 26 F to 28 F (-3 to -2 C) to avoid coil icing. Where it goes: in a branch line off the discharge line, as close to the compressor as possible. Locating it at the compressor rather than the evaporator is what lets it reach rated capacity. Inlet strainer: available for all solder type bypass valves. Sporlan also recommends a filter-drier in the liquid line. Dimensions and weight of this unit: 12 in x 9 in x 4 in (305 x 229 x 102 mm), 4 lb (1.8 kg) Condition: New Source: Parker Sporlan Bulletin 90-40, March 2011, pages 1, 2, 3, 4, 5, 6, 8, 9 and 11. Part number, dimensions, weight and condition from this asset record.