We are a professional metal casting factory based in Baoding, China, specializing in custom ductile iron valve castings. This non-rising stem resilient seated gate valve body (concealed stem soft seal gate valve body) is our core pressure-bearing valve casting, widely used in municipal water supply, buried pipelines, fire protection systems, sewage treatment, water conservancy and industrial fluid pipeline projects. As the main housing of soft seal gate valve, this gate valve body holds the wedge disc, stem, sealing components and bonnet inside. The non-rising stem design saves installation space, which is especially suitable for underground buried pipelines. It controls the opening and closing of water media, bears PN10 / PN16 pipeline working pressure and guarantees bubble-tight sealing and long service life for pipeline networks.

Our non-rising stem resilient seated gate valve body casting is mainly produced by resin sand casting, our mature and reliable process for heavy-duty valve castings. The full production workflow includes pattern making, moulding and core assembly, molten iron smelting, spheroidizing and inoculation treatment, pouring, shakeout, sand removal, shot blasting cleaning, stress relief annealing, precision machining, dimension inspection and hydraulic pressure testing. Resin sand casting provides smooth casting surface, stable delivery dimensions, compact internal metallographic structure and low rate of shrinkage porosity, sand hole and other casting defects. We can also arrange lost foam casting for bulk orders according to customer drawings and technical requirements.

Resin Sand Casting Process Steps

1. Pattern making

   Make wooden or aluminum patterns and core boxes according to customer drawings. Patterns decide the shape and delivery dimensions of the ductile iron casting.

2. Sand mixing

   Mix silica sand, furan resin and hardener uniformly in the sand mixer. The resin acts as the binder.

3. Molding & coring / core setting

   Fill the mixed resin sand into the pattern flask and core box. Make the outer mould and sand cores for internal cavities (such as valve body inner passage).

4. Self-hardening at room temperature

   The sand mixture cures by chemical reaction under room temperature, no heating required. The mould gains enough strength after curing.

5. Mould assembling (closing mould)

   Take out the pattern, place the sand core inside the mould cavity, then close and clamp the mould.

6. Melting & spheroidizing + inoculation treatment

   Melt pig iron and scrap steel in the induction furnace. Carry out spheroidizing and inoculation treatment to get qualified QT450-10 ductile iron molten iron.

7. Pouring

   Pour the molten ductile iron into the assembled mould cavity through the gating system.

8. Cooling

   Keep the casting inside the mould for a proper cooling period until the metal solidifies completely.

9. Shakeout & sand removal

   Break the sand mould and take out the rough casting; remove adhered sand from the casting surface.

10. Shot blasting

    Shot blast the rough casting to remove oxide scale, improve surface finish and reveal surface defects.
11. Stress relief annealing

    Heat treatment to eliminate internal casting stress, avoid deformation during later machining.

12. Rough & finish machining

    CNC machining for flanges, sealing faces, holes and key grooves to meet drawing tolerance.

13. Inspection & testing

    Chemical composition test, mechanical property test, dimensional inspection, visual check, NDT and hydraulic pressure test for valve castings.

14. Packing & delivery

    Qualified castings are packed and arranged for shipment.

The standard material for this resilient seated gate valve body is QT450-10 ductile iron (GJS450-10). QT450-10 ductile iron has excellent tensile strength, good elongation and impact toughness, outstanding pressure resistance, which fully meets the requirements of buried water valves. It can pass strict hydrostatic test and adapt to humid, underground and outdoor complex working conditions. Besides QT450-10 ductile iron, Baoding Guokun Machinery also supplies grey iron, alloy cast iron and aluminum alloy castings, supporting custom material standards per your drawings, GOST, EN or ASTM specifications.

As a reliable Baoding valve casting manufacturer, we produce a full range of ductile iron valve spare parts: non-rising stem resilient seated gate valve body, gate valve bonnet, butterfly valve body, silent check valve body, grooved coupling and other pipeline casting components. We own complete in-house workshops from casting, heat treatment to CNC machining, so we can strictly control quality, lead time and production cost. We accept OEM & ODM custom casting with drawings or samples. Both small trial batches and mass bulk orders are welcome.

Strict quality control runs through every production procedure of our valve castings. Our inspection scope covers chemical composition analysis, mechanical property test, dimensional inspection, visual surface inspection, wall thickness check, magnetic particle / ultrasonic nondestructive testing, and hydraulic pressure test. Every finished ductile iron valve casting will be fully inspected before shipment to ensure compliance with drawing tolerances, material certificates and technical specifications.

If you are sourcing a trustworthy China metal casting factory for non-rising stem resilient seated gate valve body and other ductile iron valve castings, please send us your drawings and inquiry. Guokun Machinery delivers stable-quality custom casting solutions with competitive prices for your valve projects.