Piston Valve Applications: Casting Systems

Piston actuated valves are suitable for a wide variety of applications. In this blog post we will look at there use in a casting systems application and provide an example of the type of valves that we would recommend for this application.

High-pressure casting systems using Piston Actuated Valves:

High-pressure casting systems carry out industrial manufacturing of sanitary fittings such as rim bowls, wash basins, bidets or shower trays.

These systems are completely automatic and can carry out all production stages without manual interventions.

The casting process consists of the following production stages:

– casting or feeding/exhausting of the slip;

– consolidation of the component and detachment from the mould;

– extraction of the component from the mould;

– washing of the mould.

The material used for manufacturing sanitary fittings is a slip – a very dense ceramic mixture made of clay and water.

Injection nozzles inject casting slip into the mould at 18 bar pressure. This occurs under high pressure.

Three different types of piston actuated valves would be used in this process as shown in the diagram below.

1) Consolidation of the component and detachment from the mould

When the casting cycle is over, valves control air at 7 bar pressure and inject it into the still closed mould in order to consolidate the component and detach it from the mould.

2) Extraction of the component from the mould

During the extraction, cycle valves control the vacuum cycle: thanks to suction generated by the injection nozzles in the mould, the component is retained until the robot picks it up and places it onto the drying bench.

3) Mould washing

Valves, working at 10 bar pressure, inject inside the circuit moulds to wash them. The mould is made of micro-porous resin; due to its permeability, it lets water filter outside thus eliminating all slip residues.

The type of valves that we would recommend for this type of application is:

You can view the V-Flow Solutions range of M&M Piston actuated valves here:

V-Flow Solutions: Piston Valves

M&M Angle seat piston valves

M&M piston valves are manufactured in Italy, using the highest quality materials for a high-quality product.

These Piston actuated valves use an external control media to pilot the actuator, where a piston valve connects directly to the main seal that closes onto the main orifice, thereby controlling the flow of liquids and gases.

V-Flow Solutions recommend M&M Piston Valves under these conditions:

Media containing dirt particles
Highly viscous media (up to 600 CST (80°E); 1 centistoke = 1 mm²/s)
High flow volumes
High temperatures
Damp environments or hazardous locations

The versions of M&M Piston actuated valves available are:

Technical Information

The main seal material used in piston actuated valves:

A modified PTFE has been the main seal material since 2004 when it replaced the original PTFE material seal.

The modified PTFE seal provides these benefits over the previous version:

Lower porosity and permeability
Fewer void spaces
Higher elasticity
Reduced deformation under load
Better chemical resistance to controlled media
Smoother surface and improved design flexibility

The standard bonnet seals consist of 2 ‘V’-shaped FKM gaskets and a package of 25% graphite-filled PTFE gaskets.

High-temperature Piston actuated valves:

M&M can offer a piston valve that can be used up to 200°C, provided that the valve pressure limits are respected.

The main differences, in regards to the materials in this design, are as follows:

Change of the actuator material: From standard PA6 to PA66 filled with 30% fibreglass
All valves with DN > 25 with fixed plug design (to withstand turbulence caused by steam at high speed)
Special design of bonnet chevrons, all are made of 25% graphite-filled PTFE