F317L Valve Manufacturer in Germany

F317L valves are used in chemical and process systems requiring greater molybdenum content and localized-corrosion resistance than conventional 316L stainless steel. ASTM A182 F317L is a low-carbon austenitic stainless-steel forged grade associated with UNS S31703, providing improved resistance to pitting and selected acidic environments.

F317L Valve for Acidic and Chloride Service

F317L contains more molybdenum than conventional 316L stainless steel.

The higher molybdenum content improves resistance to localized corrosion in suitable environments, particularly:

• Pitting
• Crevice corrosion
• Selected chloride-bearing fluids
• Certain acidic process streams

The low carbon content reduces susceptibility to sensitization during welding and thermal exposure.

F317L can therefore be considered for:

• Chemical processing systems
• Pulp and paper
• Acid transfer
• Marine process lines
• Industrial wastewater
• Process fluid piping

It should not be described as universally suitable for seawater or all concentrated acids. More highly alloyed materials may be necessary for severe chloride service.

Low Carbon Austenitic Stainless Steel Properties

F317L is an austenitic chromium-nickel-molybdenum stainless steel.

Its main characteristics include:

• Low carbon content
• Austenitic microstructure
• Higher molybdenum than 316L
• Good weldability
• Resistance to sensitization
• Improved localized-corrosion resistance compared with 316L in suitable environments
• Useful mechanical properties across a wide range of industrial conditions

The low carbon level reduces chromium-carbide precipitation during welding, helping retain corrosion resistance near welded regions.

ASTM A182 F317L Composition

Typical F317L chemistry includes:

Element	Typical Range / Limit
Chromium	18–20%
Nickel	11–15%
Molybdenum	3–4%
Carbon	0.030% max
Manganese	2.00% max
Silicon	Approx. 1.00% max
Phosphorus	0.045% max
Sulphur	0.030% max
Nitrogen	Controlled according to specification
Iron	Balance

The material designation depends on component form:

• Forged: ASTM A182 F317L / UNS S31703
• Cast 317L-type construction: ASTM A351 CG3M where specified

CG3M should be described as the cast 317L-type grade rather than “cast F317L.”

Valve Types and Construction

The current F317L range includes Gate and Globe Valve designs.

F317L Gate Valve

• Used for straight-through isolation in corrosive process piping.
• Operates fully open or fully closed.
• Options include rising stem, solid/flexible wedge, bolted or pressure-seal bonnet, and flanged/butt-weld ends.

F317L Globe Valve

• Used for flow regulation and shut-off.
• Suitable for throttling, frequent operation and process-flow adjustment.
• Can be used for compatible steam and utility service.

Technical Specifications

Parameter	Typical Specification
Forged Material	ASTM A182 F317L
UNS	S31703
Cast 317L-Type Material	ASTM A351 CG3M where applicable
Valve Types	Gate Valve, Globe Valve
Size Range	DN15–DN600
Pressure Rating	PN10–PN160 / ASME Class 150–2500 depending on valve design
Trim	F317L, Stainless Steel or hard-faced trim
Seat	Metal Seat / service-specific seat construction
Bonnet	Bolted, Welded or Pressure Seal depending on configuration
End Connections	RF/RTJ Flanged, Butt Weld, Socket Weld, Threaded
Operation	Handwheel, Gear, Pneumatic, Electric or Hydraulic where applicable
Pressure Design	ASME B16.34 / valve-specific standard
Face-to-Face	ASME B16.10 / EN 558 where applicable
Testing	API 598 / EN 12266-1
Documentation	EN 10204 3.1 / 3.2 where specified

Molybdenum Content and Corrosion Resistance

Molybdenum is one of the key differences between F317L and conventional 316L stainless steel.

Its higher molybdenum content improves resistance to localized breakdown of the passive film.

This can provide improved performance against:

• Chloride pitting
• Crevice attack
• Certain reducing acids
• Corrosive process condensates

Actual performance is controlled by:

• Chloride concentration
• Temperature
• pH
• Acid concentration
• Fluid velocity
• Crevice conditions
• Oxidizing contaminants

Increasing temperature can significantly reduce the corrosion margin even when the alloy performs well at ambient conditions.

The process medium should therefore be checked against suitable corrosion data before F317L is selected.

F317L and 316L Comparison

F317L and 316L are both low-carbon molybdenum-bearing austenitic stainless steels.

316L

316L commonly contains approximately 2–3% molybdenum and is widely used for:

• General chemical service
• Process water
• Marine atmosphere
• Moderate chloride conditions

F317L

F317L generally contains approximately 3–4% molybdenum.

The increased molybdenum provides:

• Greater pitting resistance
• Improved crevice-corrosion resistance
• Better performance in selected acidic and chloride-containing media

A useful material hierarchy for increasing chloride severity may therefore move from:

316L → F317L → higher-alloy materials such as F44 or suitable Duplex/Super Duplex

depending on operating conditions.

Chemical and Process Applications

F317L valves can be used in:

• Chemical processing
• Pulp and paper plants
• Acid-transfer systems
• Oil and gas utilities
• Industrial wastewater
• Marine process systems
• Petrochemical plants
• Power-generation auxiliaries
• Effluent treatment

Gate valves provide pipeline isolation, while globe valves are used where throttling or repeated flow adjustment is required.