TABLE l-l. Maximum Pressures and Capacities of Air Compressors
Rotary sliding vane
Rotary liquid piston
removing moisture and oil from the compressed air. Refer to chapter 4,
3.4 Separators. Separators remove and collect entrained water and oil
precipitated from the air. Refer to chapter 4, section 4.
3 . 5 Traps.Traps drain condensed moisture and oil from separators,
intercoolers, aftercoolers, receivers, and distribution piping. Refer to
chapter 4, section 5.
3.6 Air Receivers. Air receivers are tanks wherein compressed air is
discharged and stored. They help to reduce pulsations in the discharge line
and provide storage capacity to meet peak demands exceeding the capacity of
the compressor. Refer to chapter 4, section 6.
3.7 Air Dryers. Air dryers remove moisture that might condense in air lines,
air tools, or pneumatic instruments. Refer to chapter 4, section 7.
3.8 Safety Valves. Safety valves are used in a compressed air or gas
system. They must open rapidly and fully so that excessive pressure buildup
can be relieved immediately to prevent damage or destruction of the system
components. Although the terms safety valve and relief valve are often used
interchangeably, this is technically incorrect. A relief valve is used with
liquid systems. Since liquids are virtually incompressible, a relief valve is
designed to open gradually as the venting of a small amount of liquid is often
sufficient to relieve excessive pressure throughout the system. There is one
class of valve known as a safety-relief valve that can be used as either type
depending upon internal adjustments. Safety valves are found in interstages,
air receivers, and between a positive displacement compressor and any shutoff
4 CONTROLS. Control systems for air compressors vary from the relatively
simple to the extremely sophisticated. The simpler control systems, through
the use of sensors, monitor the performance of the equipment and, through the