YHP Machining Co., Ltd. · Fenggang, Dongguan
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Marine & Offshore

Corrosion-resistant and sealing-critical components for marine and offshore equipment.

Turning duplex stainless
Sealing faces after machining
Valve and drive parts
2205 · 2507 · 316LCorrosion alloys
NACEQuoted case by case
Ra 0.4 µmSeal faces
0.01 mmBore tolerance
1–1,000Typical batch

At sea a part fails for two reasons: it corrodes, or it leaks. Both are decided by material choice and by the quality of the sealing surface, and neither forgives a shortcut taken to save a setup.

We machine valve bodies, pump components, shaft seals, deck hardware, sensor housings and hydraulic fittings in duplex and super-duplex stainless, bronze and nickel alloys, with sealing faces finished rather than left as machined.

What we make here

Parts that come through this department.

Valve bodies and trimPump and impeller componentsShaft seals and housingsDeck and rigging hardwareHydraulic and pneumatic fittingsSubsea sensor housings

Typical work: traceable batches where material certificates and pressure-related documentation travel with the parts.

How the work runs

From drawing to shipping, in this order.

1
Environment reviewSplash zone, submerged or deck service decides the alloy and the surface treatment before anything is quoted.
2
Material and certificateDuplex and super duplex are bought with the mill certificate and the heat number recorded against the order.
3
MachiningDuplex is machined at low speed with generous coolant; the wrong parameters work-harden the surface and ruin the finish.
4
Passivation and checkParts pickled or passivated where specified, then measured and packed with the certificate.

Materials, equipment and inspection

The practical detail.

Materials and environment

316L, 2205 and 2507 duplex, super-duplex, Monel, bronze and nickel aluminium bronze. Passivation and pickling arranged where the drawing requires it after machining.

Inspection

Sealing faces checked with a profilometer, bores with bore gauges, geometry on the CMM. Material certificates traceable to the heat number; pressure-test requirements quoted as a separate step.

Capacity

What the department can actually hold.

Part familyTypical materialWhat decides the price
Deck and manifold fittings316L, 2205Pressure class, thread form and finish
Pump and valve componentsDuplex 2205, 2507Alloy machinability and bore tolerance
Shafts and sleeves17-4PH, 316LGrinding allowance and straightness
Structural brackets316L, 2205Plate thickness and welding prep
Seal housingsDuplex, 316LGroove finish and concentricity
Subsea small partsSuper duplex, MP35NCertification and non-destructive testing

Duplex is not stainless with a different name. It work-hardens under a dull tool, so the parameters and the tool change on the drawing, not on the shop floor.

Parts we have machined

Real components, photographed on our own bench.

Offshore hardware
Offshore hardwareDuplex · sealing faces
Valve trim
Valve trimBore and seat
Pump component
Pump componentTurning · passivated

Where the money goes

What actually drives the price of this work.

Straight answers

Questions buyers ask about this work.

Do you machine duplex without losing corrosion resistance?

Yes, but it needs sharp tooling, controlled heat input and a finish that is not left torn. Where the drawing calls for it, parts are pickled and passivated after machining rather than shipped with a smeared surface.

Can you hold a sealing face finish to Ra?

Yes, quoted against the Ra on the drawing. Tell us the seal type as well: a static O-ring groove and a dynamic lip seal do not need the same surface.

Do you pressure test?

Testing is arranged to the drawing's requirement and quoted as a step. We will not describe a part as pressure tested unless a record exists.

Keep reading

Where this usually leads next.

Request a quotation

Tell us the part and the environment it works in.

Industry fit is checked before the price is argued. Send the drawing with the service conditions and we will answer on both.