The S-tube valve has a big role to play in the concrete pumping system. Adjusting the S-tube valve has become the number one priority at the start of each shift of concrete pumping work. Following is an introduction to the adjustment of S-tube valve and replacement of other consumable parts.
1. Clearance Adjustment between Wear Plate and Wear Ring
After the pumping work of 300m3 of concrete is done, check the clearance between the wear plate and wear ring. Standard wear plate-wear ring clearance should be no more than 2mm. If the clearance value exceed this and there is even wear on the contact surface, users only have to adjust the clearance without the need to replace the wear plate and wear ring.
2. Replacement of Wear Plate and Wear Ring
a. Replace Wear Ring
I. Shut off the electric motor and take out the screen from the hopper.
II. Loosen the irregularly-shaped bolt for about 20mm. Do not loosen the bolt too much as it would cause the S-tube valve to slide axially backward. As the S-tube draws back, its bearing would exit from the bearing housing, which leads to the damage of the sealing element. Bad seal would often result in grout leakage and shortened use life of the S-tube valve.
III. Remove the annular flange and pull the S-tube valve towards the rear wall of the hopper where the wear plate is mounted. This movement would reduce the clearance between the wear plate and wear ring to 20mm. Take out the wear ring and check if the resilient spring is broken. If it is, replace it with a new wear ring.
b. Replace Wear Plate
Un-tighten all the bolts installed on the wear plate. Shake the wear plate for easy removal. Check if there is any damage to the wear plate. If there is, replace it with a new one.
Other consumable parts also need to be inspected regularly, as of the piston.