INDUSTRY COMPONENT

Valve Seat

Precision sealing component in steam generator feedwater control valves that regulates flow and prevents leakage.

Component Specifications

Definition
A valve seat is a critical sealing surface within steam generator feedwater control valve trim that mates with the valve plug or disc to create a tight seal when closed, precisely controlling high-pressure, high-temperature feedwater flow into steam generators in power plants and industrial systems. It ensures zero leakage in closed position and minimal pressure drop in open position.
Working Principle
The valve seat provides a precisely machined annular sealing surface that interfaces with the valve plug/disc. When the valve closes, the plug contacts the seat with controlled force, creating a metal-to-metal or soft-seated seal that blocks fluid passage. During opening, the plug lifts away from the seat, allowing controlled feedwater flow proportional to valve position.
Materials
Stainless steel (316SS, 17-4PH), stellite (stellite 6, 21), hardened alloys, cobalt-chromium alloys, ceramic composites for erosion resistance. Material selection based on temperature (up to 400°C), pressure (up to 250 bar), and feedwater chemistry.
Technical Parameters
ParameterTypical rangeNotes & selection driver
Leakage ClassANSI/FCI 70-2 Class IV or better
Seat Diameter25-150 mm (standard sizes)
Surface FinishRa 0.4 μm or better
Pressure RatingUp to 250 bar
Temperature Range-20°C to 400°C
Flow Coefficient (Cv)10-600 depending on size

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

Standards
ISO 5208, ANSI/FCI 70-2, ASME B16.34, DIN 3230

Parent Products

This component is used in the following industrial products

Engineering Analysis

Risks & Mitigation
  • Erosion from high-velocity feedwater
  • Cavitation damage
  • Thermal stress cracking
  • Corrosion from water chemistry
  • Seat deformation from over-torquing
FMEA Triads
Trigger: High velocity feedwater containing particulates
Failure: Erosion of sealing surface leading to increased leakage
Mitigation: Use hardened materials (stellite), install upstream filters, maintain proper water treatment
Trigger: Thermal cycling between startup/shutdown
Failure: Thermal stress cracks in seat material
Mitigation: Use materials with matched thermal expansion, implement controlled warm-up procedures

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance
±0.025mm on critical dimensions, Ra 0.4μm surface finish
Test Method
Hydrostatic testing per ISO 5208, helium leak testing for nuclear applications, flow coefficient testing per IEC 60534-2-3

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

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.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Valve Seat

6 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.

ZFA Valve
Tianjin, Tianjin, CN
Founded 2006
ISO9001 CE WRAS ISO14001 +2
Also makes: Gate/Valve, Pneumatic Actuator, Valve Actuator and 3 more
Managed by the manufacturer
Listed on the company's own website
Dongying Lake Petroleum Technology CO., Ltd
Shandong, CN
ISO GOST
Listed on the company's own website · profile compiled by CNFX from public sources
LDTD Homogenizer
Changzhou, Jiangsu, CN
Listed on the company's own website · profile compiled by CNFX from public sources
Plumberstar
Shanghai, CN
Also makes: Butterfly Valve, Heating System, Pressure Gauge and 9 more
Listed on the company's own website · profile compiled by CNFX from public sources
XIAMEN MASCERA TECHNOLOGY CO.,LTD.
Fujian, CN
Listed on the company's own website · profile compiled by CNFX from public sources
Zhuzhou Chuangrui Cemented Carbide Co., Ltd.
Hunan, 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.

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Frequently Asked Questions

What is the main function of a valve seat in feedwater control systems?

The valve seat provides the primary sealing surface that prevents feedwater leakage when the valve is closed and controls flow characteristics when open, ensuring precise regulation of water entering steam generators.

How often should valve seats be inspected or replaced?

Inspection intervals depend on operating conditions but typically range from 12-24 months. Replacement is needed when leakage exceeds Class IV standards or erosion reduces sealing effectiveness by more than 0.1mm.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification
This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

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