Product Overview

DEENPU 2″ 1502 Pressure Relief Valve — High Pressure Safety for Frac & Flowback Operations

The DEENPU 2″ 1502 Pressure Relief Valve is a critical safety device designed for high-pressure hydraulic fracturing (frac), flowback operations, well service, and stimulation applications. It is installed in the high-pressure piping system to protect pumps, manifolds, and surface equipment from overpressure conditions by automatically relieving excess pressure when the system pressure exceeds the preset relief set point.

The valve features a 2″ nominal bore with 1502 API hammer union end connections, providing quick and reliable make-up and break-out in the field. The 1502 union connection is the industry standard for high-pressure flowline and treating line connections in frac and well service operations, rated for working pressures up to 15,000 PSI. The valve body is forged from high-strength alloy steel and finished with a durable red paint coating for corrosion protection and visibility in the field.

DEENPU pressure relief valves are available with a wide range of set pressure settings from 6,000 PSI to 15,000 PSI, with standard set pressure increments available in 250 PSI or 500 PSI steps. The valve is designed to reseat automatically after the overpressure event has passed, or can be configured with a manual or remote reset mechanism depending on the application requirements. Each valve is factory-set and tested to the specified relief pressure, with a calibration certificate provided.

How the Pressure Relief Valve Works

The pressure relief valve performs a critical safety function in the high-pressure treating system during frac and flowback operations:

1. Overpressure Protection — The relief valve is installed in the high-pressure treating line, typically downstream of the frac pumps and upstream of the wellhead. It is set to open at a predetermined pressure (the set pressure) that is below the maximum allowable working pressure (MAWP) of the downstream equipment. If a blockage occurs downstream (e.g., a sand plug, a closed valve, or a frozen flowline), the pump pressure will rise rapidly. When the pressure reaches the set pressure, the relief valve opens automatically, diverting the high-pressure fluid to a safe discharge location (typically a pit, tank, or flare system). This prevents the treating line, wellhead, or downstream equipment from rupturing due to overpressure. The set pressure is typically set at 10% below the MAWP of the lowest-rated component in the system, providing a safety margin.
2. Automatic or Manual Reseat — When the overpressure condition is relieved and the system pressure drops below the set pressure, the valve reseats automatically, closing the flow path and returning the system to normal operation. The reseat pressure is typically set at 90-95% of the set pressure (a 5-10% blowdown). This prevents the valve from chattering (rapidly opening and closing) at pressures near the set point. For some applications, the valve may be configured with a manual reset mechanism that requires the operator to manually reseat the valve after it has opened. This is used in situations where the operator wants to inspect the system and confirm the cause of the overpressure before returning to normal operation. Remote reset options are also available for automated frac operations where the valve is operated from a control cabin.
3. High-Pressure Fluid Diversion — The 2″ 1502 union connections allow the valve to be installed inline with standard frac treating iron (2″ or 3″ flowline) using hammer union couplings. The discharge side of the valve is typically connected to a relief line that runs to a safe discharge location. The valve is designed to handle the full flow rate of the treating line when open, with minimal backpressure. The flow capacity of the valve is rated in terms of the orifice area and the flow coefficient (Cv or Kv), which determines the maximum flow rate at a given overpressure. DEENPU 2″ relief valves are sized to handle the full output of a single frac pump or a portion of the total treating rate, depending on the system design. Multiple relief valves may be installed in parallel to handle the total treating rate of a multi-pump frac spread.

Key Features

Applications

• Hydraulic fracturing (frac) operations — Overpressure protection on the high-pressure treating line between frac pumps and wellhead
• Flowback operations — Safety relief on flowback manifold, choke manifold, and wellhead isolation systems
• Well stimulation and acidizing — Overpressure protection during acid stimulation, matrix acidizing, and hydraulic fracturing
• Well service and workover — Safety relief on well service pump lines, cementing lines, and nitrogen pump lines
• High-pressure pumping systems — Relief valve on discharge manifold of high-pressure pumps, cement pumps, and nitrogen pumps
• Manifold and treating iron systems — Overpressure protection on frac manifold, zipper manifold, and treating iron assemblies
• Pressure testing and hydrotesting — Safety relief during pressure testing of wellhead, BOP stack, and surface equipment
• Offshore platform frac and stimulation — Compact, high-pressure relief valve for offshore hydraulic fracturing and stimulation operations

Technical Specifications

All specifications are standard configurations. Custom set pressures, temperature ranges, materials, and connection types are available on request. Contact DEENPU engineering for application-specific sizing and selection.

When Ordering, Please Specify

1. Set PressureRequired relief set pressure in PSI or MPa. Specify exact set pressure (e.g., 10,000 PSI) or range (e.g., 8,000–12,000 PSI adjustable).
2. End Connection Type2″ 1502 hammer union (standard). Other sizes and connection types (1502 x 2002, 2002 x 2002, threaded, flanged) available on request.
3. Reset TypeAutomatic reseat (standard), manual reset (requires operator to reseat after opening), or remote reset (pneumatic or hydraulic actuator for remote operation).
4. Body and Trim MaterialStandard alloy steel (AISI 4130/4140) body with stainless steel trim. For sour service, specify NACE MR0175 compliant materials (Inconel, 316 SS, or duplex stainless steel).
5. Spring MaterialStandard chrome-silicon alloy steel spring. For high-temperature or sour service, specify Inconel X-750 or other high-temperature alloy spring.
6. Service FluidWater, frac fluid (gel, slickwater, linear), nitrogen, acid, or other. Specify fluid composition for material and seal compatibility.
7. Operating TemperatureMinimum and maximum ambient and fluid temperature. Standard range: -20°F to 250°F. Extended temperature ranges available.
8. Flow Capacity RequirementRequired flow rate at set pressure or overpressure condition. Specify treating rate (bbl/min or m3/min) and fluid type for valve sizing.
9. Discharge ConfigurationOpen discharge (standard), closed discharge to line, or flare connection. Specify discharge connection type and orientation.
10. Certification RequirementsAPI 6A / 16C certification, material test certificates (MTC), hydrostatic test certificates, set pressure calibration certificate, NACE MR0175 compliance certificate, and third-party inspection (DNV, BV, SGS).

Custom Manufacturing & OEM Capability

• Non-Standard Set Pressure — Custom set pressures outside the standard 6,000–15,000 PSI range, including low-pressure relief (1,000–5,000 PSI) and ultra-high-pressure relief (15,000–20,000 PSI).
• Multiple Size and Connection Options — 1″ 1502, 2″ 1502, 3″ 1502, 2″ 2002, 3″ 2002, and other hammer union sizes. Threaded and flanged end connections also available.
• High-Temperature Service — Extended temperature range springs and seals for high-temperature frac and steam stimulation applications (up to 400°F / 204°C).
• Sour Service (H2S) — NACE MR0175 compliant materials: Inconel 625, 316L stainless steel, or duplex stainless steel body, trim, and springs for H2S-bearing service.
• Remote Operation and Monitoring — Pneumatic or hydraulic actuator for remote opening/closing. Pressure transmitter for remote monitoring of set pressure and valve status.
• Multiple Valve Manifold — Custom manifold assembly with multiple relief valves in parallel for high-flow-rate applications, with isolation valves for individual valve maintenance.
• Special Coating and Identification — Custom paint colors, RFID tagging, serialized identification, and electronic calibration records for fleet management.
• Complete Safety System — Relief valve supplied as part of a complete wellhead safety system including pressure gauges, transducers, ESD valves, and control system.

Quality Control & Testing Standards

• Material chemical composition and mechanical properties verified per batch. Tensile strength, yield strength, elongation, and hardness per API 6A.
• Body and bonnet magnetic particle inspection (MPI) and ultrasonic testing (UT) on all forgings per API 6A / 16C.
• Each valve shell hydrostatically tested to 1.5x rated working pressure per API 6A. Hold time and leak rate recorded on test certificate.
• Each valve seat hydrostatically tested to 1.1x rated working pressure in both directions. Zero leakage acceptance criterion.
• Set pressure calibration test performed on each valve using a calibrated hydraulic pressure test unit. Set pressure verified at ambient temperature and recorded on calibration certificate.
• Reseat pressure verification performed to confirm blowdown (reseating differential) is within specification (90–95% of set pressure).
• High-pressure gas test (optional) using nitrogen or helium at 80% of set pressure for critical applications. Leak detection by bubble test or pressure decay.
• Spring rate and load verification on each spring to ensure consistent set pressure and reseat performance.
• Dimensional inspection of bore diameter, union thread dimensions, face-to-face length, and overall dimensions per API 6A tolerances.
• Material test certificates (MTC) per EN 10204 3.1 provided for all pressure-bearing and structural components.
• Third-party inspection and certification by DNV, BV, SGS, or ABS available upon request.

Frequently Asked Questions