Editorial Technical Reference

Disc/Seat Assembly

This page explains how Disc/Seat Assembly is classified within Fabricated Metal Product Manufacturing. Technical values and manufacturer relationships are research references; confirm the current specification and supplier evidence for each order.

Technical Definition & Core Assembly

The critical sealing interface within a pressure relief valve that opens to release excess pressure and closes to maintain system integrity.

Representative product image. Confirm appearance and specifications with the manufacturer.

Product Specifications

Technical details and manufacturing context for Disc/Seat Assembly

Definition
The Disc/Seat Assembly is a precision component used in metal tank pressure relief valves. It consists of a disc (or poppet) and a matching seat that together form the primary sealing mechanism. Under normal operating conditions, the assembly maintains a leak-tight seal, preventing fluid or gas from escaping. When the system pressure exceeds a predetermined set pressure, the disc lifts from the seat, creating an opening to relieve excess pressure and protect the tank from over-pressurization. Once the pressure drops below the reseat pressure, the disc returns to the seat, re-establishing the seal. This assembly is critical for ensuring the safety and integrity of pressure systems. The materials on file include stainless steel, alloy steel, and brass. Key parameters include nominal diameter (15–100 mm), operating pressure (1.0–1.6 MPa), set pressure (0.1–1.6 MPa), operating temperature (-40 to 200 °C), leakage rate (0.01–0.1 cm³/min), seat hardness (40–50 HRC), surface roughness (0.2–0.4 µm Ra), seat and disc material (316L stainless steel), and weight (0.5–5.0 kg). These values are reference ranges and must be verified for the specific model and application. Standards such as ISO 4126-1, ASTM E18, ISO 4287, and ASTM A240 are referenced for testing and verification, but do not imply certification. Always confirm model-specific values and standards with the legal manufacturer or supplier.
Working Principle
Under normal operating pressure, spring force holds the disc against the seat, creating a seal. When system pressure exceeds the set pressure, the force on the disc overcomes the spring force, lifting the disc from the seat. This opens a passage for excess pressure to escape. Once pressure drops below the reseat pressure, the spring force returns the disc to the seat, re-establishing the seal. The assembly operates automatically, ensuring system safety without external intervention.
Common Materials
Stainless Steel, Alloy Steel, Brass
Technical Parameters
ParameterTypical rangeNotes & selection driver
Nominal Diameter15–100 mmStandard sizes for pressure relief valves
Set Pressure0.1–1.6 MPaPressure at which the valve starts to openISO 4126-1
Operating Temperature-40–200 °CSeat material limits the upper rangeISO 4126-1
Leakage Rate0.01–0.1 cm³/minClass VI seat leakage per ISO 5208ISO 5208
Seat Hardness40–50 HRCHardness affects wear resistanceASTM E18
Surface Roughness0.2–0.4 µm RaCritical for sealing performanceISO 4287
Seat Material316LCorrosion-resistant stainless steelASTM A240
Disc Material316LSame as seat for uniform thermal expansionASTM A240
Weight0.5–5.0 kgDepends on size and material

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM
  • Disc Part
    Movable component that lifts from the seat to allow flow during pressure relief
    Material: Stainless Steel
  • Seat Part
    Stationary component that provides the sealing surface for the disc
    Material: Stainless Steel
  • Disc Holder/Stem Part
    Connects the disc to the spring mechanism and guides disc movement
    Material: Alloy Steel

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Disc/Seat Assembly.

Industrial Ecosystem & Supply Chain Structure

Complementary Systems
Downstream Applications
Specialized Tooling

Application Fit & Sizing Matrix

Operational Limits
pressure: Up to 10,000 psi (690 bar)
flow rate: Cv values from 0.01 to 100
temperature: -50°C to 400°C
slurry concentration: Up to 20% solids by weight
Media Compatibility
✓ Steam systems ✓ Hydrocarbon processing ✓ Chemical processing with compatible elastomers
Unsuitable: Hydrofluoric acid environments
Sizing Data Required
  • Required set pressure (PSIG/bar)
  • Maximum flow rate (SCFM/Nm³/h)
  • System operating temperature (°C/°F)

Reliability & Engineering Risk Analysis

Failure Mode & Root Cause
Seat galling and deformation
Cause: Excessive torque during assembly or operation leading to metal-to-metal contact and cold welding, often exacerbated by misalignment, insufficient lubrication, or incompatible material pairing between disc and seat.
Disc erosion and pitting
Cause: Cavitation or abrasive wear from high-velocity fluid flow containing particulates, leading to material loss and compromised sealing integrity, typically due to improper fluid filtration, excessive pressure drops, or corrosive media.
Maintenance Indicators
  • Audible high-frequency vibration or chattering during operation indicating disc instability or partial blockage
  • Visible external leakage around the valve stem or body joint, or a persistent drop in system pressure despite normal settings
Engineering Tips
  • Implement precision alignment procedures during installation and use anti-seize compounds compatible with service media to prevent galling and ensure even seating contact
  • Install upstream filtration (e.g., 10-micron filters) and maintain fluid cleanliness to minimize abrasive wear, while selecting erosion-resistant materials like stellite or hardened alloys for high-flow applications

Indicative industry ranges for design and RFQ preparation. Confirm the exact figures and applicable standard with the manufacturer before specifying.

Compliance & Manufacturing Standards

Applicable Standards
:2015 (Industrial valves - Pressure testing of valves) ANSI/FCI 70-2 (Control Valve Seat Leakage) DIN EN 12266-1 (Industrial valves - Testing of metallic valves)

Quoted from the published standard.

Manufacturing Precision
  • Seat Surface Flatness: 0.025mm maximum deviation
  • Disc Bore Diameter: +0.01mm/-0.00mm tolerance
Quality Inspection
  • Helium Leak Test (for seat tightness verification)
  • Surface Roughness Measurement (Ra ≤ 0.8μm for sealing surfaces)

Manufacturers of Disc/Seat Assembly

2 companies list this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

DONGGUAN MISSION GAUGE & FIXTURE CO.,LTD.
Guangdong, CN
Founded 2013
Also makes: Battery Pack, Door Assembly, Pneumatic Actuator and 2 more
Listed on the company's own website · profile compiled by CNFX from public sources
Jining Zhineng Construction Machinery Co., Ltd.
Shandong, CN
Listed on the company's own website · profile compiled by CNFX from public sources

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

Technical documentation
Request current drawings, revision history, and a signed specification sheet.
Manufacturing capability
Verify equipment lists, process limits, capacity, and representative production evidence.
Inspection readiness
Confirm test methods, calibrated equipment, sampling plans, and traceable reports.
Supplier transparency
Check the legal entity, factory address, ownership, certifications, and direct contacts.

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Frequently Asked Questions

What materials are available for the disc and seat?

The materials on file include stainless steel, alloy steel, and brass. The seat and disc material is specified as 316L stainless steel, but other materials may be available depending on the application. Always confirm with the manufacturer.

What is the operating pressure range?

The operating pressure range is 1.0 to 1.6 MPa. The set pressure range is 0.1 to 1.6 MPa. These are reference values; verify for your specific model.

What standards apply to this component?

Relevant standards include ISO 4126-1 for safety valves, ASTM E18 for hardness, ISO 4287 for surface roughness, and ASTM A240 for stainless steel material. These are references for verification, not certifications.

How do I know when the assembly needs maintenance?

Signs of wear or leakage, such as increased leakage rate or failure to reseat properly, indicate maintenance may be needed. Regular inspection and testing per the manufacturer's recommendations are essential. Always consult the supplier for specific maintenance intervals.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification
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