201 Emergency Vents

The OPW 201 Emergency Vent is designed to prevent an aboveground storage tank from becoming over-pressurized by providing high-capacity venting in the event of a fire or blockage of the OPW 23, 113, 523V, or 623V. The 201 is a weighted, mushroom-style emergency vent. When the AST builds pressure, the weighted cast iron lid is forced up off its seat to relieve the pressure. When pressure is relieved, the lid lowers and is automatically reset. The appropriate 201 Series vent is determined by the emergency venting capacity requirements of the AST and the type of connection at the tank's emergency vent opening. The OPW 201 Emergency Vent is available in 4", 6" and 8" openings with female NPT, male NPT or flanged connections (8") to allow for easy installation in new or existing aboveground tanks. Various lid pressure settings determine the initial venting of the valve.

Download the OPW 201 Series Catalog Page

201 Emergency Vents

201 Emergency Vents

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  • Features & Benefits
  • Ordering Specifications
  • Replacement Parts
  • Downloads

Features

  • Automatically Resets – Weighted cast iron cover reseats once the pressure in the tank is relieved.
  • O-Ring Sealed Cover with Teflon®-Coated Seat – Ensures smooth, tight sealing surface and reliable service life.
  • Octagon-Shaped Base for Ease of Installation – Wrenching surface is integral to the vent body.
  • Aluminum Body and Cast Iron Lid.
  • Epoxy Powder-Coated Cover – Prevents rusting of the cover to protect expensive finishes on ASTs.
  • UL Listed - To satisfy Third Party accreditation requirements of many jurisdictions.
  • Aluminum Bodies - prevent interference with interstitial space in double-wall tanks.

Materials

  • Lid: cast iron, with powder-coated finish
  • Body: aluminum
  • Shaft: zinc-plated steel
  • O-Ring: Buna-N

Vent Guide

Model # in. mm Mounting Connection in. mm in. mm lbs. kg
201-4080 4 102 8 oz. Female NPT 5-5/8 143 5-1/4 133 9.2 4.2
201-6080 6 152 8 oz. Female NPT 6-7/8 175 7-3/4 197 18.5 8.4
201-8080 8 103 8 oz. Female NPT 7-5/8 193 10 254 33.5 15.2
201M-4081 4 102 8 oz. Male NPT 5-7/8 143 5-3/4 133 9.2 4.2
201M-6081 6 152 8 oz. Male NPT 6-7/8 175 7-3/4 197 18.9 8.6
201M-6161 6 152 16 oz. Male NPT 7-7/8 200 8-7/8 225 34.9 15.8
201M-8081 8 203 8 oz. Male NPT 7-5/8 193 10 254 33.8 15.3
201F-8085 8 203 8 oz. Flanged 4-7/8 125 13-1/2 343 42.8 19.4

Vent Capacity

Size scfh @ 2.5 psi (0.17 bar)
4" 101,000
6" 250,000
8" 471,000

Listings and Certifications

Ordering Specifications - Aluminum Body

Pressure Mounting

A

B

Weight

Model #

in.

mm

Setting

Connection

in.

mm

in.

mm

lbs.

kg

201-4080 4 102 8 oz. Female NPT 5-5/8 143 5-1/4 133 9.2 4.2
201-6080 6 152 8 oz. Female NPT 6-7/8 175 7-3/4 197 18.5 8.4
201-8080 8 203 8 oz. Female NPT 7-5/8 193 10 254 33.5 15.2
201M-4081 4 102 8 oz. Male NPT 5-7/8 143 5-3/4 133 9.2 4.2
201M-6081 6 152 8 oz. Male NPT 6-7/8 175 7-3/4 197 18.9 8.6
201M-6161 6 152 16 oz. Male NPT 7-7/8 200 8-7/8 225 34.9 15.8
201M-8081 8 203 8 oz. Male NPT 7-5/8 193 10 254 33.8 15.3
201F-8085 8 203 8 oz. Flanged 4-7/8 125 13-1/2 343 42.8 19.4

Vent Capacity

Size scfh @ 2.5 psi (0.17 bar)
4" 101,000
6" 250,000
8" 471,000

Dimensions

Replacement Parts

Part # Description
H13265M 4" O-Ring
H13266M 6" O-Ring
H13267M 8" O-Ring