Pressure Relief Vent DOT 407 Combination Pressure Relief Vent MC 307 Pressure Relief Vent

DOT 407 Vent, 3″ NPS Connection

Our 3″ DOT 407 Vents allow you to upgrade virtually any MC 307 or MC 312 tank to DOT 407 or DOT 412 venting. All the benefits of the 400 Series Vents without expensive hot-work. Flow rates are slightly less than our standard DOT 407 Vents, but are more than sufficient for most tanks. See the table below for specific flow rates. The stainless steel valve seat seals on a Teflon® encapsulated silicone “O” Ring. This “O” Ring provides complete chemical resistance and a bubble-tight seal to meet the latest DOT requirements. The unit also meets the surge requirements of 178.345-10 (b) (3). Download Data Sheet

Girard DOT407 Swivel

DOT 407 Vent, 3″ and 4″ NPS Swivel Connection

Girard Equipment vents are now available in a 3″ and 4″ swivel connection. This valve was designed to allow easy positioning of air inlet assemblies and/or pressure gauges. Pressure only and pressure/vacuum styles are available. All common repair parts are interchangeable with all other styles of Girard DOT 407 Vents. Download Data Sheet

Special “Weld-In” DOT 407 Pressure Relief Vent

Girard’s Special Low Profile “Weld-In” (LW) Series DOT 407 Vent combines an ultra-low profile, light weight design with high flow rates to meet the most demanding needs of virtually any tank. See the table below for specific flow rates. The LW Vent welds directly to your manlid, thus avoiding expensive hot-work to the shell of your tank, and is low enough to be “retro-fitted” to most any tank without having to alter the overturn protection. Download Data Sheet

DOT 407 Combination Pressure/Vacuum Relieving Vent

This spring-loaded, dual-acting pressure and vacuum relief vent provides much needed protection from a dangerous build-up of positive and negative forces, known as pressure and vacuum, on tank trailers transporting hazardous chemicals. Each vent is carefully assembled and tested to each customers’ exact specifications. Careful attention was paid to the design around the idea of a minimization of repair parts and a vent which could be easily disassembled with simple hand tools. Download Data Sheet

Pressure Relief Vent

DOT 407 Vent, 4″ NPS Connection

Our Low Profile DOT 407 Vent combines a low profile, light weight design with increased flow rates to meet the most demanding needs of virtually any DOT 407, DOT 412, MC 307 and MC 312 tank. See the table below for specific flow rates. The stainless steel valve seat seals on a Teflon® encapsulated silicone “O” Ring. This “O” Ring provides complete chemical resistance and a bubble-tight seal to meet the latest DOT requirements. The unit also meets the surge requirements of 178.345-10 (b) (3). Download Data Sheet

Girard Equipment DOT 407 Vents are Available in 4 Models:

DOT 407 Pressure Vent 25 MAWP
DOT 407 Pressure Vent 30 MAWP
DOT 407 Pressure Vent 35 MAWP
DOT 407 Pressure Vent Special Setting (40,45,50)

Click here to download DOT 407 Model Technical Bulletin

MC 307 Pressure Relief Vent

The MC 307 Pressure Relief Vent is a stainless steel, pressure actuated unit that is engineered to limit excessive internal pressure to 130 percent of tank design. The standard model vent set at 25 PSIG will exhaust 26,700 SCFH at 32.5 PSIG and conforms to the emergency venting requirement code for MC 307 tanks having a total exposed surface area up to 700 square feet. The stainless steel valve seat is equipped with a replaceable Tef-O-Sil “O-Ring.” The unit doubles as an unloading device, since the valve body is tapped 3⁄4″ N.P.T. to accommodate the addition of inlet fittings for air unloading of transports. Provision is also made for a pressure gauge to be attached to the vent body. An optional incorporation of a small vacuum section in the valve seat is also available upon request. It should be noted that this section, due to its limited size, may not be adequate enough to prohibit tank implosion. For additional vacuum protection, refer to “Girard Magnetic Vacuum Breakers” for tank transports. The entire vent is designed to be easily removed from the tank vehicle for inspection and/or cleaning. Download Data Sheet