1. This document provides maintenance guidelines for reciprocating ammonia feed pumps, including maintenance for tandem valves, plunger packing, and crank cases. 2. Tandem valve maintenance should be performed every 4 months and includes cleaning, lubricating, and replacing O-rings. 3. Plunger packing should be checked regularly and replaced every 2-2.5 years depending on quality. Packing outlet ammonia content should be monitored and packing tightened if over 12%. 4. Crank case maintenance includes checking for water, oil leaks, excessive heat, and measuring clearance of the overload protection switch.

1. RECIPROCATING AMMONIA FEED PUMP
MAINTENANCE
Author
Prem Baboo
Sr. Manager (Prod)
National Fertilizers Ltd., Vijaipur, India
Following regularly maintenance are required for Ammonia
reciprocating Feed pumps
1. Tandem valve maintenance,
2. Plunger packing maintenance.
3. Crank Case Maintenance
4. Other maintenance
1. PREVENTATIVE MAINTENANCE OF TANDEM VALVES
At least once every four months, check for proper operation by following the
preventative maintenance steps outlined below. These steps can be performed
while the actuator is in service and, in some cases, without interrupting service.
Generally by experience internal passing sound are coming from block means the
“ O” ring to be replaced.

2. 1. Clean and lubricate all internal parts. All O-rings should be replaced and
lubricated using a silicone lubricant. The bore that houses the sliding seal
assembly in the transfer case must be smooth and clean.
2. Reassemble the sliding seal assembly by pushing the base seal into the
transfer case. Place the sliding seal collar on top of the base seal so that the
raised portion of the sliding collar protrudes through the hole in the top
clamp.
3. Replace the top clamp and the spiral snap-ring.
Fig-1 Tandem Valves

3. Fig.-2., High Pressure Block

4. 2. PLUNGER PACKING REPLACEMENT
In a reciprocating pump in which a plunger is slid ably disposed within a
pumping chamber for reciprocating movement therein it is necessary to provide
packing for the plunger to prevent the leakage of liquid out of the pumping
chamber between the plunger and the cylinder wall. It is a common practice to
provide a bore in the head of the pumping chamber for the packing box.
However, with this type of construction it is difficult to replace the worn packing
without removing the plunger from the head of the pumping chamber, especially
if the packing is of the closed ring type.
Reciprocating pumps use various method of packing as their sealing
methodology. For packing to be reliable it must always be in contact with
lubricant such as pump product or an external flash like steam condensate. The
flow for plunger about 120 lit/hr./plunger
Sample of ammonia plunger packing outlet should be done regularly twice in
week.
We are allowed about 12.0 % ammonia in plunger packing outlet analysis
Sample
Plunger packing outlet analysis for ammonia by lab.
Sample Points Ammonia analysis Status
Plunger No. 1 5.0% Ok
Plunger No. 2 7.0% Ok
Plunger no. 3 14.0 % Plunger packing
tightening to be done

5. About two month plunger packing tightening is required for reducing ammonia
contents in plunger outlet water.
Plunger packing life about 2.0 to 2.5 years depends upon packing quality. We are
using Inmarco packing.
Fig. 3., Packing material Enmarco
Fig. 4., Stuffing box
3. CRANK CASE MAINTENANCE

6. As you know this device can protect the pump against overload around the shaft The
reason of the overload can be as following items:
1. closing of control valve or hand valve in the discharge of the pump.
2. Suddenly increasing in the synthesis pressure.
No action can take during checking of the overload only the distance between switch
and body of crank shaft must be measure and checked in specific time intervals
Fig.5. Crank case Overload Protection switch

7. Over load Protection
Grooves

10. Water in Crankcase Oil
1. Water Condensation.
2. Worn seals.
3. Clogged Air Breather(s).
4. Worn Crankcase Packing.
5. Loose Covers
Oil Leakage from Crankcase
1. Oil Level/Temperature Too High.
2. Worn seals.
3. Worn Crankcase Packing.
4. Loose Crankcase Cover
Excessive Heat in Power End.
1. Pump Running Backward/RPM too low, Insufficient Oil in Power End.
2. Excessive Oil in Power End. Incorrect Oil Viscosity.
3. Operating Pump above Recommended Pressure 6) Main Bearings too Tight.
4. Drive Misaligned.
5. Suction dampener tracing steam closed
6. Pump RPM too Low.
7. Inadequate Ventilation.
8. Liquid end Packing Adjusted too Tight (adjustable style packing only)
4. OTHERS PROBLEMS
Like all other pump designs, reciprocating positive displacement pumps have their
own set of disadvantages with the most common being the pulsations. The
pulsating flow and pressure have specific suction and discharge piping system
requirement to ensure proper pump performance and to protect the piping and
other system components like discharge resonator and suction dampener.
(A) STUD FAILUR
1. Excessive discharge pressure.
2. Improper torqueing of nuts.
3. Shock overload caused by pump cavitations’
(B) EXCESSIVE VALVE NOISE
1. Broken or weak valve spring.
2. Pump cavitations’.
3. Air leak in inlet piping or loose bolts in pump inlet manifold.
4. Air trapped above inlet valve

11. Noisy Operation (Be sure to differentiate between liquid knock and mechanical knock -
very few knocks are mechanical on new installations.)
1. Piston or plunger loose
2. Valve noise amplified through power end
3. Pump cavitations
4. Liquid knock
5. Air leak in inlet piping
6. Loose bolts in pump inlet manifold
7. Hydraulic noise in liquid end
8. Loose or worn crosshead pins and bushings
9. Loose connecting rod cap bolt
10. Worn connecting rod bearings
11. Worn crosshead
12. Main bearing end play excessive
13. Worn gears
14. Gears out of line
15. Partial loss of prime
16. Shocks in piping system
17. Steam closed in suction dampener tracing.
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