Description

High Performance Stainless Steel Butterfly Valve — Technical Data Sheet

1. Product Overview

This high performance stainless steel butterfly valve adopts a double-offset or triple-offsetdesign. The body and principal internals are manufactured from stainless steel (standard material: ASTM A351 CF8M / 316 SS). It is designed for critical isolation and control applications in the oil & gas, petrochemical, chemical, power generation, marine, and water treatment industries. The valve offers bidirectional tight shut-off, low operating torque, extended service life, and superior corrosion resistance. Fire-safe, anti-static, and low fugitive emission designs are available as options.

Typical Service Media: Water, steam, oil, natural gas, chemicals, sour media containing H₂S, and cryogenic fluids.

2. Applicable Standards & Codes

Item	Standard / Code
Design & Manufacturing	API 609, ISO 17292, ASME B16.34, EN 593
Pressure-Temperature Ratings	ASME B16.34 or EN 12516
Inspection & Testing	API 598, ISO 5208, EN 12266
End Connections (Wafer/Lug)	ASME B16.5 / B16.47; Double Flanged: ASME B16.5 (short pattern)
Face-to-Face Dimensions	API 609 Table 2 (or ISO 5752 Short Pattern)
Fire-Safe	API 607 / API 6FA
Sour Service Materials	NACE MR0175 / ISO 15156
Fugitive Emissions	ISO 15848-1 or TA-Luft
Top Flange / Actuator Mounting	ISO 5211

3. Technical Specifications

Parameter	Specification
Valve Type	High Performance Double-Offset / Triple-Offset Butterfly Valve
Nominal Size	DN 50 – DN 1200 (2″ – 48″); larger sizes upon request
Pressure Class	ASME Class 150 / 300 / 600 (or PN 16 / 40 / 64 / 100)
Temperature Range	-196°C to +550°C, depending on seat and seal material selection
Leakage Class	Bidirectional zero leakage (metal-seated: ANSI/FCI 70-2 Class V / VI)
End Connections	Wafer, Lug, Double Flanged
Face-to-Face	In accordance with API 609 Short Pattern, or EN 558 Series 20 / 25
Top Flange	ISO 5211 with mounting bracket

4. Materials of Construction

Component	Standard Material (Stainless Steel)	Optional Materials
Body	ASTM A351 CF8M (316 SS)	A351 CF8 (304 SS), CF3M, Duplex SS (4A/5A), Inconel 625
Disc	ASTM A351 CF8M (316 SS)	Duplex SS (UNS S31803), Monel, Inconel 625 overlay or solid
Stem	ASTM A564 Type 630 (17-4PH SS)	Duplex SS, Inconel 625, Monel K-500
Seat / Seal Ring	PTFE, Reinforced PTFE (RTFE)	Graphite-filled PTFE, Devlon, Metal laminate / Inconel 718 + Graphite, Stellite hardfacing
Packing	PTFE braided / molded, Graphite	FFKM (Kalrez), Mica/Graphite combination (for high-temperature / fire-safe)
Bearings	PTFE-lined + 304 SS	Graphite-impregnated bronze, Inconel

Note: For sour service (H₂S-containing media), all pressure-containing and pressure-controlling components shall comply with NACE MR0175 / ISO 15156.

5. Design Features

Double-Offset / Triple-Offset Geometry: The sealing surfaces disengage without friction, resulting in low torque and extended service life. Triple-offset design achieves metal-to-metal zero leakage.
Bidirectional Sealing: The valve provides tight shut-off in both flow directions; either no preferred flow direction or a clearly marked preferred direction.
Fire-Safe Design: Certified to API 607 / API 6FA upon request. The primary soft seat is backed by a secondary metal seat that ensures reliable shut-off during and after a fire.
Blow-out Proof Stem: The stem is internally inserted with an integral shoulder, preventing ejection under line pressure.
Anti-Static Device: Electrical continuity is maintained between the disc, stem, and body to prevent static buildup.
Low Fugitive Emissions: Stem sealing is designed to meet ISO 15848-1 Class B or TA-Luft requirements. Optional dynamic seal monitoring ports are available.
In-Line Maintainability: Certain designs allow replacement of the seat and sealing elements without removing the valve from the pipeline (side-entry construction).
Self-Lubricating Bearings: Upper and lower stem bearings utilize metal-backed self-lubricating materials, reducing operating torque and eliminating the need for routine maintenance.

6. Testing & Inspection

All valves are tested in accordance with API 598 or ISO 5208 prior to shipment.

Test Item	Test Pressure / Criteria	Acceptance Standard
Shell Hydrostatic Test	1.5 × Rated Pressure	No visible leakage; no structural damage
Seat Leakage Test	1.1 × Rated Pressure (bidirectional)	Zero leakage or as per ISO 5208 Rate A
Low-Pressure Seat Test (optional)	0.6 MPa (6 bar) air or nitrogen	Zero bubble leakage
Fire Test (optional)	Per API 607 / API 6FA protocol	Satisfactory seal integrity after test
Fugitive Emission Test (optional)	Per ISO 15848-2	Leakage rate ≤ Class B
NDE (Non-Destructive Examination)	RT / PT / MT per ASME B16.34 supplementary requirements	Conform to relevant standards

Hold Time: Shell test minimum 15 seconds (extended for large sizes); seat test minimum 15 seconds.

7. Operation & Actuation

Operation Mode	Description
Manual – Lever / Handwheel	Standard for sizes up to DN 200, with position indicator and lockout device
Manual – Gear Operator	For large sizes or high-pressure applications, manual operation
Pneumatic Actuator	Double-acting or spring-return, 1.5× safety factor; can be equipped with solenoid valves and limit switches
Electric Actuator	Multi-turn or part-turn, available with 4–20 mA control and SIL capability
Hydraulic Actuator	For ultra-high pressure or subsea applications

Mounting Standard: ISO 5211 top flange, enabling direct coupling with any compatible actuator. A universal mounting bracket is provided.

8. Certification & Documentation

Material test certificates with full traceability (EN 10204 Type 3.1)
Factory acceptance test reports (shell and seat test)
API 607 / API 6FA fire-safe type approval certificate (where applicable)
NACE MR0175 material compliance statement
Fugitive emission type approval (ISO 15848-1)
Declaration of conformity
Installation, Operation & Maintenance Manual (IOM)

Optional Third-Party Inspection: Lloyd’s Register (LR), DNV, ABS, CCS, Bureau Veritas (BV), etc.

9. Installation & Service Recommendations

Valve Installation: Wafer and lug types are installed between mating flanges. Follow any flow direction markings; double-offset designs may feature a preferred flow direction for optimal sealing.
Flange Bolting: Tighten bolts evenly in a cross-pattern to prevent body distortion that could compromise seat sealing.
Routine Inspection: Periodically check packing for leakage; adjust gland or replace packing as required.
Spare Parts Kit: It is recommended to maintain a spare set consisting of seat ring, packing, and bearings for quick field repair.
Storage: Store in a dry, ventilated area with the disc slightly open (approx. 5–10°) to prevent permanent deformation of the seat.

10. Remarks

This technical data sheet outlines the general specifications for a high performance stainless steel butterfly valve. Final configuration, specific materials, actuator sizing, pressure-temperature ratings, and any supplementary testing shall be subject to the project-specific purchase specification and data sheet. The manufacturer shall submit detailed drawings and calculations for approval after order confirmation.

High Performance SS Butterfly Valve