Cast Iron or Steel? The Receiver is tailored for the application.
Volume 4/ Issue 1/ May 2017
The “receiver” or “tank” in a Domestic® Pump steam condensate handling unit should be of the proper material and size for the application, following industry best practices and ASHRAE recommendations. Condensate collection tanks generally come in two types of material – cast iron or steel. Both meet the highest industry standards and provide years of service. The main difference is that cast iron tanks have more than 2 percent carbon content in the iron-carbon alloy.
Close-grained cast iron is the most-used material for domestic receivers. Features include high quality, durability, corrosion resistance, heat retention, leak-tightness, machinability—and a 20-year warranty against corrosion. It is the standard for the majority of our build-to-order and stock products. The average life of a cast iron tank is 25-30 years.
Cast iron’s machinability lets us process all the receiver’s operational openings – for the condensate inlet, the pump connections, the vent, overflow, drain, gauges, switches, make-up water, etc. However, steel offers even greater flexibility for customizing tanks. The more machinable steel receivers can be easily modified for the customer’s specific application.
Black steel is a budget option for rectangular cast iron receivers, and standard for cylindrical tanks. Cylindrical receivers are dish-headed and reach up to 1,697 gallons in volume, compared to a cast iron tank’s 250-gallon maximum. Steel tanks cannot equal cast iron’s heat retention or corrosion resistance; their typical warranty is 12 months from date of installation or 18 months from shipment.
We can increase corrosion resistance for cylindrical black steel receivers with optional galvanized, epoxy-lined or stainless steel tanks. We can also insert an optional magnesium anode corrosion inhibitor, which attracts the corrosion process and extends the steel tank’s life.
Good care is important to keep the receiver in shape and provide a safe environment. Note that in Domestic Pump units, receivers must not be pressurized, and boiler feed chemicals should not be fed directly or ahead of the tank. You can easily recognize Domestic units by the gray paint – a water-based, environment-friendly enamel that coats all our units’ composites (tanks, pumps, etc).
Available options for receivers