What is Valve Handwheel?
Handwheels are most common valve actuator. Handwheels are used to actuate control valve manually where automatic controlling is out of option and also in many cases, handwheels are used to override the control system and to operate the valve manually.
There are several types of handwheels, including: handwheels fixed to the stem, hammer handwheels, and handwheels connected to the stem through gears. Due to the complex shapes of valve handwheels, stainless steel casting is adopted to produce valve handwheels.
Casting Material: 316 Stainless Steel
316 stainless steel is one of the common grades used in stainless steel investment casting process. The compositions of 316 stainless steel includes slightly increased nickel content and the presence of 2%-3% of molybdenum, which significantly increases the corrosion resistance of valve handwheels. In short, 316 stainless steel valve handwheels provides improved performance in many areas, including:
- superior resistance to chloride
- resistance to corrosive chemicals
- better resistance to cracking & Pitting
Manufacturing Process: Stainless Steel Casting
Stainless steel casting in CFS is an investment casting process, which is used for the production of stainless steel components of complex shapes. For valve handwheel parts with complicated shape, stainless steel casting is the ideal manufacturing process, as machining from a solid block is not an option.
There are several steps involved in stainless steel casting of valve handwheels. First, a wax model of the casting is prepared by injecting molten wax into an aluminum mould. Next, an investment shell is produced by dipping the model into ceramic slurries consisting of binding agents and mixtures of alumina, silica and zircon, followed by stuccoing with larger particles of these same materials. This operation is usually repeated 3-4 times until the shell thickness is adequate. Finally, the mould is baked to build up its strength. The first step involves a temperature just sufficient to melt out the wax – usually a steam autoclave is used. Further steps at higher temperature are employed to fire the ceramic mould. After preheating and degassing, the mould is ready to receive the molten stainless steel, which is poured under vacuum at a superheat of 1500℃. After solidification is complete, the investment shell is removed and pouring gate is cut. Finally, shot blast the valve handwheel to achieve smooth surface finish.
Tips on Ordering Cast Stainless Steel Valve Handwheel
- Make sure the supplier is a stainless steel foundry, not trading company. Professional stainless steel foundry can give you direct suggestions on the design, which can make casting feasible and help to save cost.
- Looking for an experienced stainless steel casting company. Only experienced casting company like CFS Foundry, can supply valve handwheels with good quality and timely delivery.
- Before ordering, make it clear that the casting process used is investment casting, not sand casting.
- Providing enough information to the supplier, such as CAD drawing, material specification, special technical requirement, order quantity, package requirement, etc.
- Ask for complete inspection report, to ensure the quality is all good before delivery.
- Working closely with the supplier until the valve handwheels are shipped.
CFS Foundry can provide custom stainless steel casting service for all types of valve handwheels. If you have any inquiry on stainless steel casting of valve handwheels or other valve parts, pls feel free to contact us!