TYPES OF VALVES

Non-backflow valve by means of a hinged disc that opens when there is pressure in the pipeline and closes when pressure is reduced, being held against the seat ring by its own weight or by external weights connected to a passing shaft through the body.

The SIESA® Lined Three-Way Ball Valve has a compact structure that allows it to be used where space limitations are an issue. It is the best choice for corrosive diverter valve applications, it has a high flow capacity with minimal pressure loss through the valve, which reduces the operating costs of the plant, it has a floating ball seat design for a closed tight in the whole pressure range and good sealing performance and easy maintenance. In addition to being applicable to gases and liquids, it works best for fluids with high viscosity and solids in suspension. These valves can be equipped with a pneumatic or electronic actuator.

Valve having a cylinder-type plug element mounted on trunnions which rotates on an axis perpendicular to the flow which allows direct flow in the open position and cuts off when the cylinder is rotated 90° and closes the conduit. Since the flow through the valve is smooth and uninterrupted, there is little turbulence within the valve and therefore the pressure drop is low.

Recommended for:

• Service (ON-OFF).
• Frequent operation service.
• Driving and cutting service, without choking.
• When quick opening is required.
• For moderate temperatures.
• When minimum resistance to movement is needed.

All valve wetted parts are coated with fluoropolymers to resist corrosion.

Valve that has a rotating disk as a plug element.

They are simple, light and low cost. The maintenance cost is also low because they have minimal moving parts.

There are two types: Wafer Type Butterfly Valve and Lug Type.

Unlike Wafer, these have holes that facilitate their installation at the end of the pipes, remaining fixed and showing great resistance to vibrations caused by high pressures. Likewise, its design allows individual disconnection of the sides of the pipe without hindering flow in other areas.

Recommended for:

• Service with total opening or closing.
• Throttled service when handling large volumes of gases and liquids at relatively low pressures.
• For frequent activation.
• When positive shutoff is required for gases or liquids.
• When only a minimum of trapped fluid is allowed in the pipeline.
• For low pressure drop across the valve.

All valve wetted parts are coated with fluoropolymers to resist corrosion.

Attached to a transverse shaft, these Wafer-type butterfly valves are mounted between flanges and are the most economical on the market. These valves have a resilient flexible rubber seat.

Valve that operates through a flexible fluoropolymer diaphragm, which is tensioned by the effect of a shaft-punch of linear movement, until it makes contact with the body, which acts as a seat.

Diaphragm valves isolate the fluid from the parts of the operating mechanism. This makes them ideal for corrosive or viscous services, since it prevents any contamination to or from the outside.

There are two types: Weir-type Diaphragm Valve and Straight-Through type.

Weir type Diaphragm Valve.

Weir valves or Saunders are preferred for throttling and produce a tight shutoff. This valve will operate with a shorter stroke and this allows the use of fluoropolymer materials for the diaphragm.

Straight passage type diaphragm valve.

The straight through diaphragm valve is for service (ON-OFF) only and has the same inside diameters and conformation as the pipe. To operate these types of valves, longer strokes are required.

In the open position, there is straight flow; when closed, the plug seats in the bottom of the valve body.

These valves are not manufactured with a fluoropolymer lining.

Recommended for:

• Choking to the desired degree of any flow (Only the weir type).
• Tolerable pressure drop in the line.
• Low Pressures.
• Liquids that can carry a large amount of solids in suspension.

All valve wetted parts are coated with fluoropolymers to resist corrosion.

Valve selected when flow regulation is required.

Globe valves are so named because of the spherical shape of their body. Although currently some designs are no longer as spherical, they retain the name for the type of mechanism.

Recommended for:

• Frequent Operation.
• Throttling to the desired degree of any flow.
• Tolerable pressure drop in the line.

All valve wetted parts are coated with fluoropolymers to resist corrosion.