Emergency Relief Valve
Emergency Relief Vents Manufacturer
As emergency venting devices for installation on storage tanks with a VRV to protect against hazardous excess pressure but minimize the loss of gas/vapours. Also suitable as replacement of a manhole. It does not protect against the hazard of explosion or stabilized burning.
Emergency Relief Valve is a highly developed emergency pressure relief valve with high flow capacity. It is primarily used as a safety device for emergency pressure relief for storage tanks, containers, silos, and process engineering equipment; it offers reliable protection against overpressure and prevents impermissible product vapour loss close to the set pressure.
Features Of Emergency Relief Valve
- Non-sparking design (available with brass ring options too).
- Corrosion Resistant Construction. Positive sealing soft seat inserts.
- Locking mechanism optional on request to prevent unauthorized access.
- The self-aligning cover closes automatically when pressure is 10% below overpressure
- Carbon steel base construction is available for welding to the tank roof.
- Flanged as per ANSI 816.5 #150 RF as Standard, other connection types available on request
Introduction :
Introduction to Emergency Relief Valves
Emergency Relief Valves (ERVs) are fundamental safety tools formulated to secure pressure-retaining equipment, as exemplified by storage tanks, pipelines, and industrial vessels, from abnormal pressure rise. In the event of an unexpected pressure spike or abrupt pressure fluctuations—often caused by equipment failure, fire, or rapid chemical reactions—ERVs open without human intervention to release excess pressure, thereby reducing the risk of catastrophic damage such as explosions or structural damage.
As opposed to standard pressure relief systems, ERVs are widely adopted as a last line of defense and are engineered to handle high flow rates in emergency situations. They are especially important in industries where volatile gases, flammable liquids, or hazardous chemicals are stored or processed. By offering rapid pressure relief while minimizing product loss, ERVs play a vital role in ensuring operational safety, environmental protection, and regulatory compliance.
Features of fidicon’s emergency relief valve
- The articulated cover dispenses a stationary hinged point, secures accurate resealing, and enhances protection.
- The cover cannot be detached from the base.
- opens effortlessly to create a vast, uncluttered access route to the tank.
- Leak-resistant diaphragm assembly ensures low vapor emission losses to 1 CFH at 90% of threshold.
- Enduring PTFE seal endorsed by a non-asbestos cushion disc for reinforced resistance and diminished seepage.
- The PTFE diaphragm protects the cushion disc from direct contact with tank vapors in chemical and low-temperature applications.
- A steel-based design is used for carbon steel units equipped with a welded and fabricated stainless tip on the outer rim of the nozzle to enable a corrosion-protected sealing surface.
- Elective rustproof steel bases for chemical and freezing-point applications.
- Flange mounting dimensions conform to either API 650 or ANSI 150#.
- An optional vacuum valve is offered with the cover.
Emergency Relief Valve: Specifications & Standards
- Pressure activation threshold
- The valves shall actuate at an established pressure threshold to reduce excess trapped pressure safely.
- Regularly used pressure settings include under the guideline of the system’s Maximum Allowable Working Pressure (MAWP).
- Flow rate capability
- Measured in the highest flow rate, the valve can vent safely during abnormal conditions.
- Typically quantified in SCFM (standard cubic feet per minute) for gases or kg/hr for liquids.
- Structural material
- Usually composed of carbon steel, stainless steel, or bronze, conditioned on the medium and ecological parameters.
- Needs to withstand corrosion, pressure, and temperature extremes.
- Effective Temperature Range
- Built to perform reliably under varying temperature conditions.
- Materials and seals need to tolerate defined temperature ranges (e.g., -50°C to 200°C).
- Leak resistance/sealing integrity
- Valves are tested for nominal leakage less than the set point pressure.
- Aligns with industry norms such as API 527 (seat tightness testing).
- Reset pressure
- Upon opening, the valve must reposition at a defined pressure (commonly around 90–95% of set pressure).
- Maintains pressure regulation, conserving product.
- Connection Types
- Typically provided with flanged, threaded, or welded ends to match industry piping systems.
- Certification and Compliance
- Should comply with global or regional safety codes:
- ASME Section VIII (Pressure Vessels)
- API 520 / API 521 (Sizing and safety relief systems)
- ISO 4126 (Safety devices for protection against excessive pressure)
- Type of Actuation
- Spring-loaded, pilot-operated, or weight-loaded, depending on response time and system design.
- Discharge Style
- May be open, vented, or connected to a closed discharge system based on environmental safety or containment needs.
Materials of construction
Common Body Materials:
- Carbon Steel (ASTM A216 WCB)
- Suitable for general-purpose applications
- Offers good mechanical strength and durability
- Stainless Steel (ASTM A351 CF8/CF8M)
- Excellent corrosion resistance
- Ideal for chemical, pharmaceutical, and food industries
- Performs well in aggressive or high-purity environments
- Aluminium
- Lightweight and corrosion-resistant
- Commonly used for storage tanks and low-pressure applications
- Bronze / Brass
- Good for non-corrosive or mildly corrosive applications
- Often used in marine or utility services
- Hastelloy, Monel, Inconel (High-Alloy Steels)
- Specialized alloys for highly corrosive or high-temperature environments
- Common in petrochemical, offshore, and aggressive chemical services
recommended disposal of emergency relief valve
- Clean and Decontaminate:
Remove all residue of process media. Use proper cleaning agents to ensure safety.
- Disassemble Components:
Separate metal, plastic, rubber, and electronic parts for correct disposal or recycling.
- Handle Hazardous Waste Carefully:
If exposed to toxic or hazardous substances, dispose through certified waste handlers.
- Recycle When Possible:
Scrap metal parts can be recycled. Non-hazardous valves may be refurbished or reused.
- Follow Regulations:
Always comply with local and national environmental laws and keep disposal records.
Conclusion
The emergency relief valves play an important role in maintaining the safety and the smooth operation of pressurized systems. They automatically vent off excessive pressure when required, preventing equipment failure, environmental damage or injury to those in close proximity. The solution to ensuring that everything works as supposed to is selecting the right valve, that which is appropriate to the system, materials and safety regulations. These valves, with proper maintenance and periodic inspections, are always prepared to serve their purpose when it is necessary the most, thus constituting an important element of any secure industrial facility.
FAQs
- Carbon Steel: Suitable for general industrial applications where corrosion is minimal.
- Stainless Steel (e.g., SS304, SS316): Offers excellent resistance to corrosion and is widely used in chemical, food, and pharmaceutical industries.
- Bronze or Brass: Common in lower-pressure systems and non-corrosive environments.
- Hastelloy, Monel, or Inconel: High-performance alloys used in aggressive chemical services or extremely corrosive conditions.
- Stainless Steel (17-7 PH or SS316): Chosen for its strength and corrosion resistance.
- Inconel X-750: Preferred in high-temperature or highly corrosive applications for long-lasting elasticity.
- Metal-to-Metal (Stainless Steel, Hardened Alloys): Used in high-temperature or steam service.
- Soft-Seated (PTFE, Teflon®, Viton®, EPDM): Provides better sealing for gas or liquid service where tight shutoff is needed.
- non -rusting steel : often used in bolts and nuts and internal parts that resist corrosion
- High – grade alloys: these are applied in high – strength uses or in corrosive environments that require high resistance
- chemical compatibility : The material should be resistant to the chemical exposure of the fluid or gas being transported.
The pressure setting is the set pressure at which the emergency relief valve is engineer to open. It provides safety of the system by automatically releasing the built-up pressure before it becomes critical or unsafe.
Set pressure is commonly founded on the maximum allowable working pressure (MAWP) of the vessel or system. It is usually placed at or just below the MAWP, and must comply with international standards, including API 520, ASME Section VIII, or ISO 4126.
Fidicon emergency relief valves may be furnished with adjustable pressure settings over a defined range. Nevertheless, it has to be adjusted by a qualified person and re-calibrated to the certification standard. Illegal modifications can cancel the warranty or legality.
The set pressures available with Fidicon are extensive, usually 0.1 bar up to 50 bar (higher by special order), depending on valve size, type and planned service conditions. We have the capacity to store low-pressure storage tanks and high-pressure process systems.
Yes. The physical property of the media (gas, vapor, or liquid), flow characteristics, and backpressure all require pressure settings and valve sizing. Fidicon has valves that are calibrated and certified to every kind of service.
Absolutely. Fidicon emergency relief valves are designed and certificated to meet international standards, such as API, ASME, PED (EU), ISO and local codes. We make sure that pressure settings are adjusted to the safety standard of all target markets.
Periodic check and testing is essential.We suggest calibration yearly or as recommended by your safety policy at the plant. Fidicon also provides in house and on site test facilities to maintain compliance and safety.
Yes. Each valve can be set at the factory to the specified pressure before final shipment. All individual units are fitted with an official test certificate and calibration validation document, making them ready to be instantly installed.
Yes, the size usually conforms to some international standard like API 2000, ISO 28300, or ASME Section VIII that may offer advice on sizing, flange connections, and flow performance
Absolutely. Most manufacturers can provide custom face-to-face dimensions, flange drilling patterns and nozzle sizes to fit particular equipment or retrofitting needs.
Yes, size has a straight effect on flow capacity. Bigger valves are available to pass higher volumes at discharge, thus they are applicable in high-pressure systems, or large volume systems.Valves that are undersized might not be able to relieve pressure effectively, and this can cause equipment damage
This is dependent on size and material.To illustrate, a 6-inch valve measure some 400 600 mm and have a weight of 30 80 kg, depending on the construction material such as stainless steel or carbon steel.
Yes, in some applications low-profile valves might be needed, particularly in vertical spaces that are tight.Manufacturers provide such options nevertheless, maintaining sufficient relief capacity.
You ought to communicate the following:
- Rate of relief required
- Tank or vessel sizes
Yes, a valve that is not of the correct size might not be safe as per the code, and it can lead to non-conformance with the industry standards or regulatory compliance. Make sure that a qualified engineer checks the sizing.
