The triple safety valve (Fig. 1) performs the following functions:
- - divides the air line coming from the compressor into two main and one additional circuit;
- - automatically turns off one of the circuits in case of damage or violation of its tightness; maintains compressed air pressure in intact circuits and ensures that they are replenished with air from the compressor;
- - maintains tightness in all intact circuits in case of damage or violation of the tightness of the supply line; feeds an additional path from both main paths.
Disassembling and assembling the valve
To disassemble the triple protective valve, it must be clamped in a vice with soft jaws by the mounting bosses, loosen the screws 19 for fastening the upper protective covers 2, and then, holding them with your hand, unscrew the screws 19 and remove one and then the other cover.
If the protective covers are not removed by themselves under the action of springs 21, light tapping on them with a copper or wooden hammer is allowed.
The rest of the valves 3 and diaphragm 6 can be easily removed from the housing
To disassemble the auxiliary circuit valve, body 1 must be turned 180° in a vice and clamped.
Then unscrew the screws, remove the cover 11 and take out the valve 8 with the spring 14, the guide 13, the plate 15 and the membrane 9.
Return valves 7 are removed from the housing 1 after dismantling with special round-nose pliers of the thrust ring 17.
On the surface of body parts, cracks, hairlines and other defects visible to the eye are not allowed.
Details must be cleaned of rust and burn marks. All rubber parts must be replaced with new ones.
The order of assembly of the triple protective valve is reverse to disassembly.
Assembly of valves, rubber o-rings and other rubber parts must be done carefully to prevent damage. The presence of scratches, cuts and other defects on the surface of these parts is not allowed.
Adjusting screws 5 must be screwed into the covers before adjustment during assembly to a depth of 9 mm from the upper plane of the covers.
Adjusting and checking the triple safety valve
Install the safety valve in triplets on the test bench and connect according to the diagram shown in (fig. 3). Then apply and release air three times into port 1 at a pressure of 0.75 MPa.
Adjust the bypass pressure of the main circuits, for which air is supplied to outlet 1 at a pressure of 0.56 MPa, then gradually unscrew the adjusting screw 5 (see Fig. 1) first in the water circuit until pressure appears in outlet 21, then in the other circuit until the appearance of pressure in port 22.
To adjust the pressure in the additional circuit, supply air to outlet 21 or 22 at a pressure of 0.51 MPa and gradually unscrew the adjusting screw of the additional circuit until pressure appears in outlet 23.
After adjusting the triple safety valve, fix the adjusting screws 5 with paint and close them with rubber plugs 4.
To check the tightness of the triple safety valve, air must be supplied to outlet 1 at a pressure of 075 MPa. the pressure in ports 21, 22 and 23 should become equal to the pressure in port 1
Bleed air from port 1, ensuring that the pressure at ports 21, 22 and 23 does not drop. Then bleed air from ports 21 or 22, and the pressure at port 23, 21 or 22 must not drop.
Next, you need to re-set the pressure to 0.75 MPa in outlets 1, 21, 22 and 23 and bleed air from outlet 23, while the pressure in outlets 1, 21 and 22 should not fall below 0.42 MPa.
Check the tightness of the triple safety valve with saponification.