lubricant divider valves

Application

The SA-V valve is an ellectrically operated change-over valve used in dual-line systems.

When used in dual-line centralised systems the valve works in conjunction with the SG-A switching device shown below.

Product Features

• Function 4/2-way
• Powered with a geared DC motor
• Working pressure max. 400 bar

Design

Operation by means of a geared DC motor with high torque ensuring reliable action even under unfavourable operating conditions (e.g. low temperatures or viscous lubricant).

The valve has a short operating time and a short stroke during the change-over action and is therefore not subject to premature wear.

Each of the plunger end positions is electrically monitored by a limit switch.

The motor's overrun and direction of rotation do not affect the limit switch setting or the operation of the change-over. A transformer, rectifier and automatic cut-out are incorporated for connection to a AC 110-127 V or 200-240 V supply.

Application

The SG-A switching device is used as a differential pressure switch in dual-line centralised lubrication systems. When the differential pressure reaches 50 bar, the switch is activated and the control valve changes over to the second line.

Product Features

• Switching pressure differential 50 or 100 bar
• Working pressure 400 bar

Design

The SG-A switching device is a hydraulically operated valve mounted on a common base plate with a limit switch to sense when a predefined pressure differential has been reached.

Function

In a dual-line lubrication system there are 2 main lines:

• one line under pump pressure and
• the other line relieving back to the grease reservoir.

The function of the electrical SG-A switching device is to reverse the flow of the dual lines by signalling the change-over valve SA-V (shown above) to change over.

Application

The DR4 is a hydraulically operated directional control valve for use with dual-line centralised lubricatioin systems.

Function

The valve consists of two sections. A flow control portion that directs the flow of lubricant from the pump to one of the supply lines and a pressure control portion that contains the spring loaded piston against which the pump pressure is directed.

The reversing valve change-over pressure is governed by the spring load which can be adjusted to suit the installation. When all the dual-line divider valves in the system have moved in one direction, pressure will build up on a pilot piston which acts against a toggle. When the vertical force of this toggle equates to that of the spring, it will snap over into the opposite position. This directs a pilot flow onto one end of the flow directing piston and relieves its other end to the reservoir, thus moving it over to direct the flow of lubricant to the opposite supply line and relieving the originally pressurised line back to the reservoir. A limit switch is mounted near to the reversing valve and this switch is actuated by a pin attached to the flow directing piston. When this moves to either make or break the switch, a signal is sent to the system controller to stop the pump and start a pause period.

On the DR4 valve (non-return system), the two pipelines do not return to the reversing valve but the reversal pressure is sufficient for the operation of all the measuring valves. This unit is factory set at 310 bar unless it is previously known that higher pressures are required.

Application

The SA-K is a hydraulic change-over valve to use with dual-line centralised lubrication systems. The design of the 4/2-way valve ensures a permanent flow of the lubricant through the internal passageways, thus avoiding the possibility of the change-over valve becoming inoperative due to the hardening of old lubricant in the internal passageways.

Product Features

• Function 4/2-way
• Hydraulically controlled
• Working pressure adjustable up to 250 bar or up to 350 bar
• Motion indicator.

Function

When one line is pressurised the other line is depressurised. As the pressure builds up in the pressurised line it will reach the pressure at which the change-over valve was set. At this point the valve changes over hydraulically and the previously pressurised line is now relieved and depressurised and the previously depressurised line is pressurised.

The change-over pressure is adjustable up to maximum of 250 and/or 350 bar by means of a pressure relief valve. It is necessary to ensure that the change-over pressure does not exceed the max. delivery pressure of the lubrication pump being used. The respective position of the 4/2-way valve can be monitored by using one limit switch or two electrical switches and enables the pump to be switched off on completion of the lubrication cycle.