Pressure Control Valves

Pressure limiting or bypass valves

When machining metals, coolants that consist of oils or emulsions are usually used. The precisely regulated coolant pressure on the tool ensures that the lubricating coolant achieves the best results on the valuable workpiece even at the highest cutting speeds. This is due to the reproducible tolerance and dimensional accuracy as well as the highest surface quality of the workpieces in series production.

On the other hand, the metal chips – even from the deepest blind holes – can only be rinsed out safely with the precisely regulated coolant pressure. This ensures perfect cooling of the tool cutting edges and prevents premature tool wear.

Our SPB and (3) HPB series pressure control valves ensure precise pressure control regardless of the amount of coolant. The coolant requirement on the tool can fluctuate enormously, depending on the machining cycle in which the tool is located: e.g. during the tool change cycle, switch tool on and off, feeds, etc. The excess coolant is returned to the coolant tank via the valve without pressure fluctuations being recognizable. On the one hand, the pressure regulating valves supply the system with a precise coolant pressure, on the other hand they protect the pipes and pumps against damage caused by overpressure due to their operating principle. That is why the valves of this series are referred to as pressure limiting valves (DBV). Since the valves are installed in the return of the coolant supply, they are also called bypass valves.

The pressure control for the 3-HPB valves is done manually; thus only one pressure level can be selected at a time. The valves are operated electropneumatically: the set pressure is switched on and off via a power supply, e.g. with 24 V.

The pressure control is active when the voltage is switched on and the valve is open when the voltage is switched off. When the valve is off, all of the coolant flows into the tank; this is called a pressure-minimized circulation circuit. This circulation switch is always suitable for soft start of the positive displacement pumps or for changing tools and workpieces if no coolant is required.

We offer a two-pressure control as an accessory. This module can be retrofitted to any valve. This enables the user to switch between two system pressures.

The bypass valves of the SPB series operate electropneumatically and are controlled by a setpoint signal (e.g. 0-10 V or 4-20 mA). The full range of the pressure control range can be continuously covered. The use of these valve types makes sense if the user requires more than two different system pressures. An electrical setpoint device (SWG-10 BCD) is available as an accessory, with which up to seven setpoints can be adjusted if required. The SPB valve type is often used together with frequency-controlled positive displacement pumps. The valves take over the lightning-fast pressure control and at the same time provide burst protection. In this system, the frequency-controlled pumps deliver the required amount of coolant as required: a particularly energy-efficient combination for the user. The electricity costs of the pump are minimized and the heat input into the coolant is significantly reduced. This series is mainly used with the coolant medium group consisting of oils or emulsions.

Options

Many DBVs are available with an SAE connection according to DIN ISO 6162, instead of a socket thread. Instead of galvanized steel, stainless steel is often available as the housing material. The prop valves are also available as IO-Link versions. Various adapter plates, special pressure gauges, or additional safety valves complete the range of options.

DBV valves are available in a nominal width of 8 to 65 mm, with a pressure control range of maximum 400 bar. The bandwidth of the flow factor (KV value) ranges from 1.1 to 60 m³/h.

The technical design of the valves is media and application specific. Can't find a suitable product on our homepage? Just contact us and choose from a variety of variants and special designs that are not listed on our website. There is certainly something suitable for your request.

Pressure reducing or inline valves

Several valves are often connected to a central supply with a fixed pressure level. This is not a problem if all valves work synchronously and always require the same pressure levels. However, if valves have to work with different pressure levels at the same time, pressure reducing valves are required. For this purpose, a pressure reducer is installed in front of each tool. Since the valves are not installed in the bypass but in the same line as the tool, the pressure reducing valves are also called inline valves. Many pressure reducers are designed for inlet pressures of 200 bar. They are able to “dim” the pressure up to 5 bar. Each valve works completely independently - with the result that neighboring valves are not affected in any way during operation.

The pressure reducing valves of the 3-HPI series are actuated electropneumatically. The set pressure can be switched on and off via a power supply, e.g. 24 V DC. When the voltage is switched on, the pressure control is active; when the voltage is switched off, the valve is closed by spring actuation. With the 3-HPI valves, the pressure is controlled manually; thus only one pressure level can be selected at a time. We offer a two-pressure control as an accessory. This module can also be retrofitted. With it, the user can even switch between two system pressures.

The pressure reducing valves of the SPI series operate electropneumatically and are controlled via a setpoint signal (e.g. 0-10 V or 4-20 mA). This means that the full range of the pressure control range can be covered continuously. The use of these valve types makes sense if the user requires more than two different system pressures. An electrical setpoint device (SWG-10 BCD) is available as an accessory, with which up to seven setpoints can be adjusted if required.

Pressure reducing valves are available in a nominal width of 8 to 32 mm, with pressure control ranges of a maximum of 400 bar. The bandwidth of the flow factor (KV value) ranges from 1.1 to 24 m³/h.

Application

The inline valves are often used in central supply systems when a single pump has to supply several tools with different coolant pressures at the same time. The coolant medium group, which consists of oils or emulsions, is mainly used. In general, the valves are also suitable for other liquids and gases.

The technical design of the valves is media and application specific. Can't find a suitable product on our homepage? Just contact us and choose from a variety of variants and special designs that are not listed on our website. There is certainly something suitable for your request.

Three-way valves

The three-way valves represent a combination of pressure limiting (bypass) and pressure reducing valve (inline). They are ideal for precise pressure control in closed systems such as pressure vessels or pressure vessels. The system pressure in a closed system can thus be precisely increased or decreased (vented) up to the full pressure level without causing pressure fluctuations or vibrations.

Three-way valves are available with a nominal width of 15 mm for pressure control ranges from 0 to a maximum of 100 bar. The flow factor is a maximum of 6 m³/h.

Application

These valves are often used on gas control test benches, but are also suitable for liquids.

Overview technical data Pressure Control Valves