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Valve & Flange Standards Guide

Marine Valve & Flange Standards Guide

JIS vs. DIN vs. ANSI Quick Reference

Shipboard piping systems vary drastically based on vessel build origin and flag state requirements. A replacement valve ordered for a Japanese or Korean-built bulk carrier (JIS) will not bolt onto a European-built vessel (DIN/EN) or American-built offshore platform (ANSI/ASME) due to differences in Pitch Circle Diameter (PCD), bolt-hole counts and face-to-face dimensions. Sourcing an incorrect standard risks costly port delays, emergency machining, or failed class inspections. Use this quick guide to verify flange ratings and dimensions before submitting a requisition.

1. Flange Standards & Pressure Rating Mapping

Standard	Common Pressure Ratings	Typical Shipboard Application	IMPA 75 Reference
JIS (Japanese)	5K, 10K, 16K, 20K	Asian-built vessels; fuel oil, ballast, seawater cooling, bilge	75 01 xx – 75 25 xx
DIN / EN (European)	PN10, PN16, PN25, PN40	European vessels; steam systems, cargo lines, engine room	75 30 xx – 75 45 xx
ANSI / ASME (US)	Class 150, Class 300	Tankers, offshore rigs, American machinery, cargo manifolds	75 50 xx – 75 60 xx

2. Dimensional Discrepancies: Why Valves Do Not Interfit

The primary reason valves fail to interchange between standards is the Pitch Circle Diameter (PCD) and the number of holes. Notice below how a 50mm/2″ valve has completely different bolt layouts across standards:

Size (DN / Inch)	JIS 5K (PCD / Holes)	JIS 10K (PCD / Holes)	DIN PN16 (PCD / Holes)	ANSI 150 (PCD / Holes)
DN 50 (2")	105 mm (4 holes)	120 mm (4 holes)	125 mm (4 holes)	120.7 mm (4 holes)
DN 80 (3")	145 mm (4 holes)	150 mm (8 holes)	160 mm (8 holes)	152.4 mm (4 holes)
DN 100 (4")	165 mm (8 holes)	175 mm (8 holes)	180 mm (8 holes)	190.5 mm (8 holes)
DN 150 (6")	230 mm (8 holes)	240 mm (8 holes)	240 mm (8 holes)	241.3 mm (8 holes)

Note: While DN 150 JIS 10K and DIN PN16 share a 240mm PCD with 8 holes, their bolt-hole diameters and flange thicknesses differ. Direct bolting requires verification of bolt clearance.

3. Marine Valve Body & Seat Material Guide

Body Material	Trim / Seat Material	Recommended Applications	Caution / Restrictions
Cast Iron (FC200 / GG25)	Bronze (BC6) or Stainless	Fresh water cooling, low-pressure bilge, ballast manifolds	Prohibited by class for sea chest or overboard lines due to brittle fracture risk
Bronze / Gunmetal (BC6 / RG5)	Bronze or Monel	Seawater suction, sanitary systems, fire main, overboard discharge	Avoid in temperatures above 200°C; higher initial cost
Ductile Iron (FCD450 / GGG40.3)	Stainless Steel (SS304 / SS316)	Fuel oil transfer, lube oil systems, general engine room piping	Moderate seawater corrosion resistance compared to bronze
Cast / Forged Steel (SCPH2 / WCB)	Stellite / Hardened Stainless	Main steam lines, boiler feed, thermal oil, high-pressure lines	Prone to galvanic corrosion in untreated raw seawater

4. Valve Sourcing & Requisition Checklist

To prevent quotation delays and ensure 100% fitting accuracy, confirm the following 6 points before requesting quotes:

Standard & Pressure Rating: State clearly if the pipe is JIS, DIN or ANSI
Nominal Diameter (DN): Metric pipe size (DN) or imperial nominal bore (inches).
Valve Pattern: Globe, angle, gate, check, storm, or butterfly.
Face-to-Face Measurement: Measure end-to-end between flange sealing faces.
Media & Temperature: Specify medium and operating temperature to select compatible seals.
Certification Needed: Indicate if an ordinary Certificate of Conformity suffices or if class society inspection is mandatory

Need Immediate Valve Sourcing or Cross-Matching?

Contact NICO Marine today to discuss your requirements. Our marine spares desk cross-references JIS, DIN, and ANSI valves with full IMPA catalog mappings and expedited port delivery.

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