Cooling

The Cooling category covers refrigeration line components, process chillers and heat exchangers supplied by Seven Star LLC from Muscat, Oman. Most of the listing is Emerson Alco series refrigerant solenoid valves and pressure transmitters, joined by a Thermal Care chiller range, an Alfa Laval gasketed plate heat exchanger and a Saginomiya thermostat used in air conditioning units. A Copeland item is listed here too, while the compressors themselves sit in the neighboring Compressors category.

Refrigerant solenoid valves and pressure transmitters

The solenoid valves here are two-way, normally closed types with solder connections, used on liquid, suction and hot gas lines. Selection is by line size, refrigerant, capacity at the operating condition and the maximum operating pressure differential. The coil is chosen by voltage and frequency and is often a separate order item from the valve body. Pressure transmitters feed the controllers that handle fan cycling, compressor staging and superheat control. They are chosen by pressure range, output signal and pressure connection.

Chillers and plate heat exchangers for process cooling

A chiller is sized on the cooling load, the leaving fluid temperature and the medium that cools the condenser. A gasketed plate heat exchanger separates two liquid circuits, for example a clean process loop and a cooling water loop, and it can be opened for cleaning or fitted with more plates when the duty changes. Plate material and gasket elastomer are chosen for the fluids on both sides.

What to send for a cooling equipment quotation

For a valve, send the model code or the line size, the refrigerant and the coil voltage. For a transmitter, the range, output and connection. For a plate heat exchanger, the flow rates, the inlet and outlet temperatures on both sides, the allowable pressure drop and the fluids. For a chiller, the load, the fluid temperatures and the design ambient temperature. Condensing units and evaporative condensers are not listed yet, but can be quoted against a specification for sites in the GCC.