Pressure Reducing Regulators
Pressure reducing regulators make up approximately 85% of all regulator applications. The purpose of the pressure reducing regulator is to reduce a higher pressure to a lower pressure.
Pressure is created by either a compressor or a pump depending on the fluid. The pressure must be great enough to go from one point in the system to another, passing through various components in the system and account for any pressure loss across the system.
Simply stated there is always going to be an excess of pressure available to the system that, in many cases, must be reduced to a lower pressure to be used by the system. In many applications a pressure reducing regulator can control a process better than a control valve.
Pressure Reducing Regulators – common sizes and configurations
Typical sizes for pressure reducing regulators vary from ¼” up to 6.0”, however regulators above a 2.0” size become cost prohibitive when compared to a control valve. The exception is when the location is such that a control valve is not a reasonable choice.
Pressure reducing regulators come in various configurations including pressure reducing, differential pressure reducing with both positive and negative bias. Differential pressure reducing regulators are used where the outlet of the regulator must be maintained at a set difference, either above or below a reference pressure.
A common example would be a steam atomizing regulator. If a burner system is designed to operate using number 6 or bunker C fuel oil, the only way to burn that oil is by mixing it with steam. The differential pressure reducing regulator will control a positive bias of about 1 bar keeping the steam pressure higher than the oil pressure throughout the firing sequence of the burner.