These function valves allow air pressure to gradually increase when a compressed air line is restarted after it has been vented for any reason (i.e. at the end of work, after an emergency stop or when adjusting the system). This gradual pressure increase, or slow start prevents shocks to the system which can occur when full working pressure is immediately introduced, thus saving wear and preventing injury to users or components. Each cylinder thus protected gradually returns to the position it stopped when the system was vented.
Working pressure: 40 to 150 PSI
Temperature Range: 5°F to 140°F
Sutable fluids: compressed air
Body: nickel-plated brass
Base: nickel-plated brass with thread sealant on tapered components
Pneumatic Slow Start Isolated Component Valves are mounted to the supply port of the control valve or the common supply line of several associated valves. Therefore the action of the fitting is immediate and controls directly the designated cylinders.
Thus the pressurization speed of the control valve, or group of valves, can be adjusted to an optimum. When the system is pressurized after an emergency stop, cylinders return to their end-of-stroke position one after the other depending on their resistive forces.
When the cylinder air has been vented, pressure is at zero. When the system air is restarted, the pneumatic slow start fitting allows a gradual buildup of pressure into the selected cylinder. Resulting in the cylinder’s slow return to its extended or retracted position.
An internal needle valve is utilized to accomplish the gradual buildup of pressure in the system. Adjusting the needle sets the rate of fill. The setting is determined by the requirements of the installation.
When the pressure in the system is at 2/3 its maximum, the slow start fully opens. The operating pressure is maintained and a full flow rate is assumed until the system air is cut off and vented.
The isolated component slow start valve is mounted directly to the inlet of a control valve, it provides slow start protection to a select cylinder. Thus the rate of pressurization to a specific cylinder may be individually controlled.
Adjustment requires only basic tools:
1. Secure the piston with a 5.5mm (7/32") open end wrench.
2. Adjust the needle (valve opening time) using a hex key while holding the piston with the open end wrench.
3. A 1.5mm hex key is required for the 1/4" size and a 2.5mm hex key is required for the 3/8" size. Wrench flats are 5.5mm on both sizes of valves. Maximum torque for hex key: 8 in. lb.