We help you protect your equipment and personnel from explosions and process overpressures.
Our unique explosion relief doors are engineered to afford superior pressure relief protection for your valuable assets.
For Explosion Protection, the number and size of doors required is a dependent on many factors for the particular application. These may include
- Explosive nature of material in your process
- Volume of air or gas flow (ACFM)
- Strength of the process vessel
- Dust concentration
- Click here for more information
For Overpressure Protection due to process errors not related to burning materials, click here.
Our technical staff can assist with the selection of the correct door size for your applications.
Who Needs an Explosion Relief Door?
Our explosion relief doors protect your equipment and personnel from explosions.
Explosions Due to Deflagration
An Explosion is the bursting or rupturing of an enclosure or a container due to the development of internal pressure from a deflagration. (From NFPA 68, Chapter 3)
Burning Starts the Potential Explosion Process
The following burning process causes overpressures that could result in explosions:
- A sufficient amount of combustible dust or gas (fuel)
- When disbursed in a closed enclosure (vessel)
- With a sufficient amout of oxidant (oxygen or other like gas) and
- Subjected to an energy source (spark) of sufficient energy
- Will burn away from that spark at a certain speed
- And develop an overpressure within that enclosure.
- If the velocity of that propagating pressure wave is less than the speed of sound, it is called Deflagration.
- If the vessel is infinitely strong, a Maximum Pressure (Pmax) will be developed within the vessel.
- A “Deflagration Index” (Kst) of a dust or a Deflagration Index (Kg) of a gas can be computed.
- These Deflagration Index numbers can be used to compare and calculate the relative severities of different materials.
Burning with Excess Overpressure Causes Explosions
If the vessel is not infinitely strong, the pressure from the deflagration will burst or rupture the enclosure, defined as an Explosion. .
PSD Doors Help Avoid Explosions:
- If equiped with a Vent opening of sufficient size and strength to relieve that developing pressure, the enclosure will experience a Reduced Pressure (Pred) below the potential Maximum Pressure, avoiding bursting or rupturing (Explosion) of the enclosure.
- PSD doors are Vents that use the Kst or Kg and Pmax values of the fuel with the characteristics of the vessel and any connected ducts to design and built hinged Vents that release the pressures safely below the Explosion pressures.
- PSD uses NFPA 68: Standard on Explosion Protection by Deflagration Venting or guidance from FM Global Engineering to design explosion vents that protect your facilities and employees.
Explosions due to Operational Errors
Process overpressures, (unlike pressures from burning dusts or gases that can cause explosions) stem from sequencing errors when opening or closing processing ducts and valves during production or cleaning.
- Overpressures from these errors can cause damage to seals, bellows, and gaskets.
- PSD Doors have sucessfully been used to alleviate such damage.
- If dusts or gases are not in the system or at levels below the minimum explosible concentration (MEC), we can size a PSD door to reduce your down times.
Process Overpressures in the Petroleum Industries
- Excess Nitrogen Blanket Pressures, Not Explosions or Deflagrations
- API (American Petroleum Industry) Oil Separators and their lift (sump) stations use the PSD doors as accessable covers to preserve the protective nitrogen blanket that covers waste waters in this process. Contact us for more specific details.
Features of Our Explosion Relief Doors
Over 5,000 installed and most pperating in the world since 1975.
PSD’s unique explosion relief door is engineered to afford superior pressure relief protection for your capital equipment and personnel.
It employs a combination magnet and pre-loaded spring relief mechanism that furnished outstanding reliability and repeatability. This repeatability prevents costly downtime if there is either an overpressure or deflagration initiated event.
Our unique explosion relief doors are engineered to afford superior pressure relief protection for your captial equipment.
Dual Purpose Design
- Provides Pressure Relief Protection for Explosive Conditions with Dusts and Gases
- Provides Over-Pressure Relief for Upset Conditions when purging or changing the process conditions
- Serves as an emergency access door (opens and closes conventionally) with fingertip manual releases
- When shut, door is present to open between 6” Water Gauge to 24” Water Gauge
Many Materials To Choose From
- Door frames of stainless steel, carbon steel, aluminum as required
- Door panels of stainless steel or aluminum
- Wide variety of gasket materials available
- Custom gasket design when required
- Door frame configuration designed to minimize installation cost
High Temperature Designs Available
- Standard design temperatures from:
- -65F (-54C) to 180F (82C)
- -65F (-54C) to 250F (121C)
- -65F (-54C) to 400F (204C)
- High temperature designs -65F (-54C) to 1000F (540C)
Lightweight Door Panels
- Standard panel weights less than 2.5 lbs/sq. ft.
- Honeycomb Panel Construction
- Quick response to over-pressures because of the low inertia of the door
Two Standard Frame Sizes
- Frames can be welded or bolted (typically on 4” centers) to the housing or vessel.
- 3 inch or 4-1/2 inch frame sizes (adds 6 inches or 9 inches to overall door panel size)
- Available in custom sizes for your specific application
- Comes Fully Assembled
- Frame Bolts in place (can also be welded)
- For New or Retrofit Installations
Critical Hardware Is All Stainless Steel
- Stainless steel latch springs, hinges, fasteners
Self-lubricating Sleeve Bearing
- Nylon sleeves are used on all critical moving parts (for lower temperature applications) to ensure reliable reaction.
- Floating, spring loaded door panels compress flexible gaskets to a rigid frame, insuring a good seal.
- Standard Buna-N Nitrile, SBR, Viton, Silicone or Silica (ceramic) gaket materials are available for a variety of applications
Food Grade Door Designs Available
- Doors have flush inside surfaces to minimize material buildup
- Many FDA, USDA, NSF required metal types available
Protective Accessories Available
- Protective Cages to surround the volume of an open door if activated
- Alarms switches to indicate an open door to a remote site or control room