Fisher 9500 instruction manual Troubleshooting Guide, Fault Possible Cause Correction

9500 Valve

Instruction Manual

Form 2433

November 2007

Table 4. Troubleshooting Guide

Fault	Possible Cause	Correction
1. Leakage out sides of	a. Hub seals require adjustment.	a. Adjust using Hub Seals portion of Adjustments
valve (at thrust plates)		procedures.
between thrust bushings	b. Taper pins are not sealed.
and shaft.		b. Remove valve from line and re-seat taper pins or install
		new taper pins using Maintenance procedures.
2. Leakage out sides of	a. Flange gaskets used.	a. Check to see if flange gaskets are being used; if so,
valve (at thrust plates)		remove gaskets.
between valve body and	b. Partial O-ring bead on liner faces damaged.
thrust bushings, leakage		b. Replace liner using Maintenance procedures.
at flanges, faces, or both
3. Leakage through	a. Hub seals require adjustment.	a. Adjust seals using Hub Seals portion of Adjustments
disc/liner seal		procedures.
	b. Linkage requires adjustment.
		b. Refer to Linkage portion of Adjustments procedures.
	c. Actuator has insufficient torque output to close disc
	against pressure drop. (Actuators are selected to have	c. If possible, check shutoff at lower pressure drops. If
	sufficient torque output to shut off the flow against a	shutoff is obtained at low pressure drops, but actuator
	specific pressure drop, not necessarily against the	stalls and does not produce full disc rotation at service
	maximum allowable pressure drop. Be sure that the	pressure drop, actuator output torque is too low. For piston
	pressure drop for which the actuator is selected is not	actuators, it may be possible to increase output torque by
	being exceeded.)	increasing supply pressure. Do not exceed maximum
		allowable supply pressure of actuator.
	d. Liner has been damaged by flowing medium or other
	valve parts damaged by being subjected to service	d. Inspect and replace parts using Maintenance
	conditions beyond those for which valve is designed.	procedures.
4. Valve shaft will not	a. If actuator does not stall, but shaft does not rotate, the	a. Refer to the actuator instruction manual to remove
rotate	spline teeth on the valve shaft are sheared.	actuator cover plate. Replace valve shaft using
		Maintenance procedures if spline teeth are sheared.
	b. If actuator stalls, shaft is binding in bushings due to
	linkage misalignment caused by excessive wear of linkage	b. Replace linkage parts.
	parts.
		c. Check actuator operation with no pressure applied to
	c. If actuator stalls and linkage is not misaligned, actuator	the valve. If valve now functions properly, actuator is too
	may have insufficient output torque to rotate disc against	small.
	flow.
5. Valve shaft rotates, but	Taper pins (or drive shaft spline for coated-disc	Inspect and replace parts using the Maintenance
valve does not control	constructions) have been sheared due to obstruction to	procedures.
process fluid	disc rotation or other internal parts damaged by being
	subjected to service conditions beyond those for which the
	valve was designed.

5.If taper pin (key 15) ends are peened, grind off the peened portions. Driving from the smaller end of the pins, drive the pins out of the disc (key 3) and shaft (key 4).

WARNING

Once the shaft has been removed, the disc may fall from the valve body, causing personal injury or disc damage. Support the disc before removing the shaft.

6.Pull the shaft out of the valve body. If the shaft cannot be pulled from the valve body, drive the shaft

out but use care to avoid upsetting the end of the shaft.

7.Remove the disc from the valve body.

8.Remove the liner (key 2) from the valve body.

Some Type 9500 valves have the liner bonded to the valve body. If the valve has a bonded liner, burn or chip out the liner.

To strip the liner out with solvent, use Dynasolve 185, or equivalent solvent. (Dynasolve is a product of DYNALOYt Inc.). Cover the valve with solvent bath or enclose the solvent bath around the liner. Remove all adhesive after the liner has been removed.

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