Pentair FNS Plus FNSP 24 Owner's Manual page 7

2. Cleaning with water:
a. Using a garden hose, thoroughly flush off all contaminated diatomite from the filter element surfaces.
3. Cleaning with muriatic acid:
Working with muriatic acid can be dangerous. When cleaning elements always wear rubber gloves and eye protection.
Add acid to water, do not add water to acid. Splashing or spilling acid can cause severe personal injury and/or property
damage.
a. A stiffening of the fabric caused by mineral deposits is usually referred to as "liming up". It usually is due to deposits of
either magnesium or calcium or both. Removal of these deposits may be accomplished by soaking the filter elements in six
(6) parts water to one (1) part hydrochloric acid (muriatic acid).
b. Wear rubber gloves and eye protection when mixing the solution, and handling or rinsing the filter elements.
c. Soak for at least four (4) hours in a plastic tub or pail.
d. Rinse filter elements thoroughly in tap water.
4. Reassemble:
a. Starting with the "SMALL GRID" element, place the element on the bottom spreader in the position marked "SMALL
GRID" using the "foot print" pattern as a guide for proper location.
b. Continue positioning the remaining elements onto the spreader in the same manner as the small element.
c. After all elements have been positioned on the bottom spreader, place the plastic template over the element spouts. This
will keep the elements positioned correctly.
d. Position the top manifold over the elements with the stand pipe inlet port pointing in the direction of the small element.
Using moderate force push down on the manifold to seat it on to the elements. Ensure template is not caught or trapped
between manifold and element spouts.
e. Replace the two nuts and the two plastic stand-offs, (if equipped).
f. Replace the completed element assembly into the filter tank.
I. CLEANING THE INTERNAL AIR BLEED TUBE.
1. Rinse the air bleed tube with water to clean away built-up debris. Normally, this is all that is necessary to properly clean the
tube.
J. CLEANING THE HIGH FLOW™ MANUAL AIR RELIEF VALVE.
1. Turn the pump off and shut off any automatic controls to ensure that the
system is not inadvertently started during servicing.
2. OPEN THE HIGH FLOW™ MANUAL AIR RELIEF VALVE UNTIL IT
SNAPS INTO THE FULL OPEN POSITION, THEN WAIT UNTIL ALL
PRESSURE IS RELIEVED.
3. With the High Flow™ manual relief valve attached to the filter tank, pull
out the locking tabs and remove the valve stem and cover assembly with a
counter-clockwise and lifting motion, see Figure 3.
4. Clean debris from the valve stem and body. Ensure that the filter tank's air
passage is open by inserting a 5/16 in. drill bit through the valve body.
Ensure that the O-rings are in good condition, properly positioned, and
lubricated with a silicone base lubricant.
5. Reinstall the valve stem and cover assembly with a downward and
clockwise motion until it snaps into position.
Rev. G 6-27-03
WARNING
7
Figure 3.
P/N 190033