Graco EQ300C manual Repairing the Diaphragm Valve, Perform the Pressure Relief Procedure

Repair

Repairing the Diaphragm Valve

NOTE: The diaphragm (17C127 – EQ300, 17C128

–EQ600) can be replaced without removing the assembly from the panel. You will need an 8 mm Allen wrench for the EQ600S and a 6 mm for the

EQ300S.

1.Perform the Pressure Relief Procedure, page 8 .

2.Loosen all 4 Allen-head cap-bolts evenly and then remove them completely while supporting the canister of the diaphragm valve.

3.Replace the diaphragm (natural rubber compound) and hand-tighten it as far as possible to establish the alignment with the canister.

NOTE: There are two shims between the diaphragm and the actuator. Keep the shims and reuse them (they do not come with the replacement diaphragm). Do not cause any pre-load or torque on the diaphragm by over-tightening it in a misaligned position.

4.Insert all 4 Allen-head cap bolts but do not tighten them.

5.Apply more than 80 psi (5.5 Bar, MPa) air pressure to the regulator inlet to cause the piston to retract.

6.With the piston retracted, hand-tighten the 4 Allen-head cap bolts.

7.Release the air pressure.

8.Tighten the cap-bolts in an alternating pattern (see image below) to 80 +/- 8 in-lb (9 +/- 0.9 N•m). This will cause a slight bulge in the diaphragm between the canister and the stainless steel casting.

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9.Test and confirm that the unit is working properly.

NOTE: This can be done using only water to charge the equipment – there is no need to use abrasive for this test.

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