Return Systems: Ensuring you have the correct specs
by Katie Ladas
March 22, 2024
Having the right specs for your Return System is critical
Written by Barry Victor, PROS Parts Founder and President
Return System is a term used to describe the components that are required to replenish the water required to operate steam boilers. During normal operation, a boiler is constantly turning water into steam. Steam is directed through pipes to various machinery which use it as a source of heat energy. This heat could be used to heat air to dry garments, or to boil solvent in the distillation process, or perhaps it is used to heat a press or ironer surface for finishing garments or flatwork. Determining the correct specs can be complicated, but it’s important to have the right size. A Return System that is too small can cause the boiler to shut down; one that is too big results in unnecessary costs.
No matter how the steam is used, once the heat energy has been removed from the steam it is turned back into hot water called condensate. This hot water is directed back towards the return system where it is stored in a tank until the boiler level controls call for more water.
A return system can come in a variety of sizes, shapes, materials, and configuration options. The basic components in a return system include a tank with a stand, a level gauge, a high-pressure water pump and a water level control valve. This blog will describe the various components and help you navigate the options so you can pick the best solution for your return system components.
The most important decision is sizing the return system. These systems generally will match a specific tank size with a specific pump and are designed to accommodate a range of boiler sizes. The chart below lists different systems based on the size of the boiler in boiler horsepower (BHP). Calculating the correct size can be complicated. If your installation is unique due to longer piping runs from the boiler to the equipment, PROSParts can help define the specs and provide customized systems. Contact us for help in these situations.
As you can see, a typical drycleaning shop boiler with a 10 BHP capacity can usually get by with a tank of only 33 gallons and a pump with a 1/2 horsepower motor. Notice that the sizing of the components is not proportional to the size of the boiler. If that was the case a 20 BHP boiler would require a 66 gallon tank and a 1 HP pump motor. In practice, the increase from a 10 to 20 BHP boiler requires only about a 20% larger tank and a 50% more powerful pump.
While we are talking about the tank, keep in mind they are available in either a vertical orientation to save floor space or a horizontal orientation for plants with more room to spare. The standard tank material is 11 GA steel, but if you are willing to pay a little more it can be supplied with 3/16” thick steel which should offer a longer service life. In some cases, an installation may warrant making the tank out of stainless steel due to harsh water conditions or a desire for extremely long life.
The pump supplied with the system is typically a turbine style pump capable of supplying a high pressure stream of water back to the boiler to overcome the internal pressure present while the boiler is in operation. These pumps are available in single or three phase for various voltage and hertz electrical supplies.