11．Maintenance 11.1 Troubleshooting Guide; Precaution For Maintenance And Inspection - Yoshitake GD-46 Series Instruction Manual

１ １．Maintenance
１ １． １ Troubleshooting guide
Problem
Reduced pressure
is higher than the set
pressure
Low flow rate
External leakage
１ １ ．２

Precaution for maintenance and inspection

 WARNING
(１) Completely discharge the pressure inside of the product and piping before disassembly and
inspection. Disassembly and inspection must be conducted by an experienced professional.
※Residual pressure, if any, may blow out the fluid, causing bodily injury or contamination on
surroundings.
(２) Never touch the product with bare hands when hot fluid is used.
※Hot fluid may cause burns.
 CAUTION
(１) For troubles other than those described in 11.1 Troubleshooting guide, contact us.
(２) During disassembling, internal fluid flows out. Discharge it into a suitable container.
※Fluid spills will contaminate surroundings.
(３) When starting operation after interval of an extended period, turn on a faucet and check the
water supply pressure.
※In case of a trouble such as poor water pressure, adjustment work must be done by an
experienced professional.
(４) Synthetic rubber is a consumable part. The replacement interval of the synthetic rubber part
greatly varies depending on the use conditions. The general guide for the replacement
interval is shown below.
※ Refer to "12. Exploded drawing" for the numbers in brackets.
GD-46 is recommended to be replaced at the same time of the replacement of water meter.
Possible cause
１．The cap (17) is left in water pressure
check status.
２．Diaphragm (7) is damaged.
３．Spindle O ring (6) is damaged.
４ ． Foreign object is pinched between
valve (2) and valve seat. Valve or
valve seat is damaged.
１．Sliding movement of valve stem O ring
(5) is disturbed by water scale,
deposits, etc.
２．Strainer (19) is clogged.
３．Pressure is set low.
４．Water shut off valve (41) is closed.
１．Set screw (23) is loosened.
２．Valve cap (12) is loosened.
３．O ring (13) is damaged.
４．Strainer cap (21) is loosened.
５．O ring (22) is damaged.
６． Union nut (33), (34) or (41) is loosened.
７．Gasket (30) or (43) is damaged.
８．Pressure gauge joint (24) is loosened.
９．Foreign object is stuck in pressure
gauge joint (24).
Recommended replacement interval
3 years
5 years
１．Invert the cap (17) so that its flat surface is on
upside.
２．Replace the diaphragm with a new set.
３．Replace the diaphragm with a new set
４．Remove the foreign materials.
If the valve (2) is damaged, replace it with a
new one.
If the valve seat is damaged, replace the
valve body (1) with a new one.
１． Clean the inside of the valve body and replace
the diaphragm with a new set.
２．Clean the strainer (19).
３．Adjust the pressure following the adjusting
steps.
４．Open the water shut off valve (41).
１．Retighten the round head screw (23).
２．Retighten the valve cap (12).
３．Replace the O ring (13) with a new one.
４．Retighten the strainer cap (21).
５．Replace the O ring (22) with a new one.
６．Retighten the union nut (33), (34) and (41).
７．Replace the gasket (30),(43).
８．Remove the pressure gauge joint (24). Apply
seal tape to the threads and attach the joint to
the valve body (1).
９．Replace the pressure gauge joint (24) with a
new one.
Parts name/number
Diaphragm set, Valve (2)
O rings (13),(22),(18)
Gaskets (30),(43)
－12－
Corrective action
■EPDT-166f■