A bleed valve is a simple fluid handling device used to relieve pressure, vent fluid or bleed air from a closed system. These functions are generally necessary before any maintenance or repair work can be conducted on a pressurized fluid line. The design of a bleed valve resembles a pipe plug with a screw threaded in from the top. The screw-like component is actually the valve stem, which rotates in and out to close and open the flow path through the threaded valve body. It has a weep hole located above the orifice that allows vented fluid to escape the system.
NOTE - This style of bleed valve is only safe for use with non-toxic system media. The stem threads are not sealed and media may leak out of the stem.
Bleed valves are essential components of fluid handling systems across a wide range of industries. Below, we highlight some of their typical applications.
Bleed Valve Application #1: Relieving Pressure Upstream of a Pressure Gauge or Instrument
In both high-pressure and low-pressure fluid systems, it is important to vent pressure before an instrument is removed or a control device is calibrated. Otherwise, it may release pressure suddenly (which can cause employee injury or equipment damage) or affect calibration conditions (which can lead to inaccurate calibration). Bleed valves enable operators to relieve the system pressure slowly, predictably, and safely.
Bleed valves are often used in conjunction with block valves. These valve assemblies are known as block and bleed valves. They consist of block valves and a bleed valve; the block valves are used to isolate the downstream components from the energy or pressure source, while the bleed valve is used to relieve the pressure.
Bleed Valve Application #2: Hydraulic Systems and Closed Liquid Systems
Closed fluid systems are susceptible to developing trapped air or gas pockets. These pockets can negatively affect system operations, including those in pumps, motors, and fuel systems. System operators can facilitate the removal of entrapped air by installing bleed valves at high points in the system. The valves open to allow the air to escape the system and close when bleeding is finished.
Bleed Valve Application #3: Filter Drains
The filters in air and gas systems are generally used to remove particulates. However, if they are designed with a standard pipe plug at the bottom of the housing, they may also collect condensates and other liquids that can fill them up and cause them to stop working. Installing a bleed valve in place of the pipe plug allows the liquid to drain out, which extends the overall service life of the filter. If the liquid is not environmentally friendly, a hose can be attached to the outlet of the bleed valve to direct the liquid into a suitable capture vessel.
Choose Bleed Valves at SSP
Bleed valves are key to achieving and maintaining efficient and safe operations in fluid systems. Want to learn more about bleed valves or looking to implement them in your system? SSP, provides compact and cost-effective bleed valve solutions with the following features and specifications:
- 316 stainless steel or Alloy 400/405 construction
- Light vacuum to 10,000 psig working pressures
- Various end connection styles and sizes
- Safety backstop screw
- Tube stub, hose barb, or no tube stub outlet options
- Optional tee-bar handle
All of our products are made in America using materials sourced from American suppliers. Our American made commitment allows us to maintain greater control over product and process quality, which means better products, lower costs, and shorter lead times for you.