Slip on forged steel flanges with antirust oil coating are the practical workhorse of marine piping systems, where components travel by sea and sit on site for months before installation. A slip on forged steel flange is slipped over the pipe end and welded with two fillet welds, which makes alignment faster than weld neck flanges and explains their popularity in shipbuilding, ballast and cooling water systems.

Because marine projects are supplied worldwide by sea freight, every flange in this range is coated with antirust oil that protects the machined surfaces from humidity and salt atmosphere during the whole voyage.

Our slip on forged steel flanges are produced to ASME B16.5 in carbon steel A105 and stainless steel 316L, and the antirust oil coating is applied after final inspection so that the sealing face arrives in the same condition it left the workshop. For direct seawater contact, stainless steel 316L is recommended, while A105 with protective coating serves the many closed and treated water systems on board.

• Slip on design allows fast positioning and fillet welding, cutting installation time in marine outfitting
• Antirust oil coated surfaces survive long sea freight and open storage without corrosion
• 316L stainless option for direct seawater and aggressive marine media
• Face finish preserved by the protective coating until the joint is assembled
• Class 150 to Class 600 coverage matches typical shipboard pressure systems
• Full material certificates and hydrostatic test reports included

Slip on forged steel flanges for marine service are inspected for dimensions, face finish and coating condition before the antirust oil is applied. Material certificates and hydrostatic test reports accompany every shipment, and classification society inspection can be arranged for shipbuilding orders.

Marine suppliers choose our slip on forged steel flanges because the antirust oil coated surface arrives clean and protected, and the documentation matches the requirements of shipyards and class surveyors.

Slip on forged steel flanges are faster to fit and align than weld neck types because the pipe simply slides into the hub before welding. For shipboard systems with many small bore connections this saves significant outfitting time.

The antirust oil forms a thin protective film on the machined surfaces that blocks humidity and salt air. It is easily removed with solvent or degreaser before installation.

For direct seawater service we recommend 316L stainless steel slip on forged steel flanges. For closed treated water systems, A105 with antirust oil protection is an economical and proven choice.

Yes. We can arrange inspection and certification by classification societies such as ABS, DNV, LR, BV and CCS for marine service orders.