Precision Casting

Home » Technology » Casting

Casting Process

Casting means pouring molten metal into a refractory mold with a cavity of a shape to be made and allowing the metal to solidify. After solidified, the desired metal object which called casting is taken out from the refractory mold. Most of WHM’s components of orifice fittings and valves are made from steel, iron, or Aluminum alloy. There are mainly two processes of castings: Investment Casting and Sand Casting.

Investment Casting(lost-wax casting) is used to make mechanical components such as valves, gears, ratchets, and parts, weighing up to 150kg(330lb). Base on the melt temperature of wax and sand binder used, there are 3 types, Type L-W, M-S, and L-S.

  1. Type L-W:
    applies low-temperature-melted industrial waxes with water-glass. The method is used to produce carbon steel parts such as the valve body. Also, it is to replace another traditional casting method – sand casting. L-W casting is normally used to produce parts weighing between 5kg (11lb) and 150kg (330lb).
  2. Type M-S:
    applies medium-temperature-melted industrial maxes with silica sol (M-S). M-S casting is suited for stainless steel and some special materials. It is used to produce parts with high accuracy requirements and good surface finishing such as internal valve parts. The part weighs between 100g (0.22lb) and 20kg (44lb). Its cost is higher than the L-W casting.
  3. Type L-S:
    applies low-temperature-melted industrial waxes with silica sol (L-S). L-S is used to produce stainless steel parts with big sizes, such as valve body. The cost is between L-W and M-S casting.

Sand Casting

Sand casting is the most traditional method of casting. A variety of materials including carbon steel, alloy steel, stainless steel, iron casting, brass alloy, and aluminum alloy castings can be used for the sand casting. Typical applications involve machine bases, large turbine impellers, plumbing fixtures, and numerous components for agricultural and railroad equipment, valve body and sprocket.

Type investment Casting Sand Casting
Waxes melt temperature Medium (≥60°C) Low (<60°C) Low (<60°C) none
Binder Silica sol Silica sol Water glass Water glass or resin etc.
Surface Roughness (Ra µin) 250-500 500-1000 1000-5000 1250-5000
Dimensional Casting Tolerance Grades * 4-6 6-8 7-9 8-10
Suitable material stainless steel & special alloy material stainless steel carbon steel Almost all alloys
Appropriate weight lb 0.05-50 2-200 10-300 ≥10
Example valve internal parts, complex shape valve body bonnet valve body, bonnet valve body, bonnet, Sprocket
Cost High Medium Low Lowest

*ISO 8062-3:2007 (GB/T 6414-2017)Castings—Dimensional tolerance and General dimensional and geometrical tolerances and machining allowances

WHM has been specialized in casting business and developed a network of partners for precision casting components since 2006. We have a professional team consisting of casting engineers engineers to control the key manufacturing process. The casting engineers use the technology of Computer Simulation Solidification to design the economical mold, core, and system of pouring. The following pictures show an example of a computer simulation status of a 2 inch ANSI Class 1500 valve body.

Though the First Article Sample process and after the X-ray inspection, section-cut verification and hydraulic test based on API the 2”1500# valve body is successfully completed.

WHM can supply casting products made of steel, aluminum, stainless steel. Our solid business relationship with domestic foundries allows us to acquire a fair price and reliable quality for your products.

The following varieties of casting products are what we have been supplying to our global clients. Your custom designs are also accepted. For assistance, please contact us through e-mail or call us at +86-21-6892 456.

Investment Casting (L-W process) - Single Chamber Orifice Fitting and Valve Body

Material: ASME SA 216 Gr WCC carbon steel

Investment casting (L-S process) - Valve body machined

Material: ASME SA351 Gr. CF8M Stainless Steel

Investment casting (M-S process) - Valve parts machined

Material: ASME SA351 Gr. CF8M stainless steel

Sand casting- Sprockets and API 6A body 2-1/16” machined

Material: Ductile cast iron ISO 1083 SG 550-5 and steel casting ASTM A487 CA15/4C

Sand casting parts - Aluminum Alloy

Scroll to Top