Drain Standpipes

A standpipe is a vertical, open-ended pipe attached to a pipeline to act as a pressure regulator, ensuring that the pressure head at that point cannot exceed the length of the pipe. For washing machines, a drain standpipe taps into the nearest drainpipe; it measures around 2-inches in diameter; is typically 30-36 inches in height; and it has a built-in trap.

The Necessity of a Drain Standpipe

A drain standpipe or washbasin is required for all washing machine installation. Drain standpipes and washbasins are used for washing machine systems, but drain standpipes offer cleaner, quieter draining and of course, a more attractive/neat appearance. According to professionals, a drain standpipe or washbasin should be a minimum of 34 inches high to avoid the possibility of siphoning and back-up water. The standpipe is typically larger than the drain hose so the drain hose will fit into the standpipe. In many cases, the drain hose may be secured with duct tape to prevent leaks around the connection. The materials used to make drain standpipes are typically durable enough to handle high pressures and hot and cold temperatures.

Wet Standpipes vs. Dry Standpipes

There are two basic types of "standpipes" including: wet standpipes and dry standpipes. Wet standpipes are pressurized on a continuous basis and water flows through continuously. Dry standpipes are mostly used by the fire department. A dry standpipe does not carry water on constant basis and it is not pressurized on a constant basis. A dry standpipe is only pressurized in case of a fire emergency and it is typically attached to a fire hydrant on the street, or it may be freestanding in some cases. Wet standpipes are readily available for use by building occupants in case of a fire emergency. If a dry standpipe happens to be present in a structure, it is typically found in the stairwell.

Types of Drain Standpipes

When we think of standpipes in terms of "drain standpipes" for washing machines, they are very basic/standard pieces of equipment. The design isn't complicated, and there aren't too many distinct "types" of drain standpipes. Most drain standpipes for washing machines share the same simple design and they are usually made from the same types of durable materials. In fact, drain standpipes are so basic that they can even be made from scratch as long as they are the appropriate height and diameter and they are made from the appropriate materials. The differences between store-bought drain standpipes are usually in size/length and manufacturer.