Troubleshooting - Stafsjö D2G Instrucciones De Instalación Y Servicio

C3 Maintenance
Inspect the valves on regular basis for any leakages. Seat and box packing are wear parts that have to be replaced
regularly. The interval for both inspection and replacement depends on the application and operating data such as
pressure, temperature, erosion, chemical, mechanical effect of the media on the materials in the knife gate valve and
on how often the valve is operated.
If a leakage is detected in the stuffing box area, re-tighten the nuts on top of the gland according section B7. If the
leakage does not stop or if any other leakage is detected, the valve needs to go through maintenance.
Make sure to implement necessary safety precautions for the personal if any leakage is detected on an
installed valve, see section C.1
Danger
A threaded stem is used on hand wheel, bevel gear and electric operated valves to open/close the valve. The stem is
greased upon delivery – make sure to grease it on regular basis.
C4

Troubleshooting

Problem
Leakage from stuffing box
packing
Leakage at
flange connection
Leakage through valve
bore
Gate does not open/close
completely
Gate does not open/close
in a smooth movement
Too large force to
open/close the gate
(too high hand force as
well)
* When tightening the gland bolts: See Table section B7
Stafsjö can offer maintenance of valves. Contact Stafsjö or your local representative for further information. Stafsjö
does not accept any responsibility for the product if wear parts not tested and approved by Stafsjö are used on the
valve. Stafsjö does not accept any responsibility for the product if maintenance instructions are not followed during
maintenance.
Reason
Gland bolting too loose*
Worn-out box packing
Incorrectly installed box packing
Damaged gate
Wrong length of bolts in flanges
Loose flange bolting
Valve not centred at flange connection
Valve not parallel to flanges
Gasket not centred
Wrong gasket material
Worn-out seat/sealing profile
Valve does not close 100%
Damaged seat or gate
Fault in actuator
Fault in limit switch setting
Valve clogged
Damaged seat/sealing profile or gate
Fault in actuator
Valve clogged
Damaged seat/sealing profile or gate
Not enough air supply pressure
Not enough air flow supply
Gland nuts tightened by too high torque
Valve exposed to stress/tension
Valve clogged or deformed
Damaged seat/gate
Measure
See relevant maintenance instructions
issued by Stafsjö
Download: www.stafsjo.com
See this instruction, section B7
See Stafsjö's maintenance instructions and
relevant data sheet
Download: www.stafsjo.com
See relevant maintenance instructions
issued by Stafsjö
Download: www.stafsjo.com
See instruction for actuator (if any)
See instruction for actuator/accessories
See the relevant maintenance instructions
issued by Stafsjö
Download: www.stafsjo.com
See the relevant instruction for actuator
See relevant maintenance instructions
issued by Stafsjö
Download: www.stafsjo.com
See the relevant maintenance instructions
issued by Stafsjö
Download: www.stafsjo.com
Document: is-VALVE, 21-02-11 issue: 15