P.O. Box 40525 · Houston, Texas USA 77240-0525
Tel: 713·466·3552 · Fax: 713·896·7386
www.norriseal.com
1001-0113O — ©2013, January 2013
O
PERATING AND
M
AINTENANCE
M
ANUAL
Series 1001, 1001A, 1001XL Level Control
Page 11 of 12
Pilot output pressure gauge indicates output
pressure signal when fluid level is below
displacer on a direct acting controller OR when
fluid level is above displacer on a reverse acting
controller.
1. Balance Spring is too compressed and puts
too much pressure on the Torque Bar.
2. The displacer arm is set too high or the dis-
placer is hitting something inside the vessel.
1. Back off the spring retainer until the output
pressure signal goes off. Re-check when the
fluid level rises (direct acting) or falls (reverse
acting).
2. Check the displacer arm by moving the
leveling adjusting bar up and down. If the
adjusting bar will move in only one direction,
this indicates the displacer arm is riding
at either the top or bottom of the vessel
connection. If it moves too freely, the
displacer has become disconnected from the
displacer arm. Re-center the displacer arm in
the vessel connection.
Pilot output pressure gauge indicates no output
pressure signal when fluid level is above
displacer on a direct acting controller OR when
fluid level is below displacer on a reverse acting
controller.
1. Balance Spring is insufficiently compressed
and doesn’t put enough pressure on the
Torque Bar.
2. The displacer arm is set too low or the
displacer is hitting something inside the
vessel.
1. Compress the spring retainer until an out-
put pressure signal is indicated on the out-
put pressure gauge. Re-check when the fluid
level falls (direct acting) or rises (reverse
acting).
2. Check the displacer arm by moving the lev-
eling adjusting bar up and down. If the adjust-
ing bar will move in only one direction, this
indicates the displacer arm is riding at either
the top or bottom of the vessel connection.
If it moves too freely, the displacer has
become disconnected from the displacer
arm. Re-center the displacer arm in the
vessel connection.
Controller does not repeat at the same fluid level
after each dump and sometimes fails to either
dump or shut-off. (The torque bar does not
bounce back fast when depressed and appears
to be hard to move.)
Paraffin or debris has built up inside the level
control body.
Remove controller from service and clean out
the body with a solvent.
On interface control, the vessel occasionally
loses all fluid or the vessel overflows, espe-
cially with temperature change. The displacer
arm is free and the displacer is not hitting inside
the vessel.
The displacer is not big enough to handle the
interface differential. Close specific gravity of
two fluids and a temperature change can cause
this problem.
Provide exact specific or API gravities of both
fluids to Norriseal Engineering for exact sizing
of the displacer that should be used..
A Pneumatic Pilot bleeds air continuously.
Materia extraña debajo de la bola en un piloto de
Foreign matter under the ball on a snap control
pilot or under the peanut on a throttle control
pilot.
OR
The tru-arc ring on the snap pilot thrust pin may
have been dislocated.
Remove the pilot following the instructions in
Paragraph 2.4. Remove the two cap screws
from the bottom of the pilot. Clean the pilot
thoroughly. If a Snap Pilot, make sure the dimen-
sion between the tru-arc ring and the bottom of
the pin is 3⁄4 in. If not, gently tap the tru-arc
ring into the proper location. Reassemble the
pilot.
T A B L E 3 . T R O U B L E D I A G N O S I S
PROBLEM
SYMPTOM POSSIBLE CAUSE
CORRECTIVE ACTION
