Corken 91 Instruction manual

Model 491-107
Installation, Operation
& Maintenance Manual
Plain Style Compressors for Liquid
Transfer-Vapor Recovery
Solutions beyond products...
ORIGINAL INSTRUCTIONS IE101K
Warning: (1) Periodic inspection and maintenance of Corken products is essential. (2) Inspection, maintenance and installation of
Corken products must be made only by experienced, trained and qualified personnel. (3) Maintenance, use and installation of Corken
products must comply with Corken instructions, applicable laws and safety standards. (4) Transfer of toxic, dangerous, flammable or
explosive substances using Corken products is at user’s risk and equipment should be operated only by qualified personnel according
to applicable laws and safety standards.

Warning
Install, use and maintain this equipment according to Corken’s instructions and all applicable federal, state, local laws
and codes. Periodic inspection and maintenance is essential.
Corken One Year Warranty
CORKEN, INC. warrants that its products will be free from defects in material and workmanship for a period of
one year from date of installation, provided that the warranty shall not extend beyond twenty-four (24) months from
the date of shipment from CORKEN. If a warranty dispute occurs, the DISTRIBUTOR may be required to provide
CORKEN with proof of date of sale. The minimum requirement would be a copy of the DISTRIBUTOR’S invoice to
the customer.
CORKEN products which fail within the warrant period due to defects in material or workmanship will be repaired or
replaced at CORKEN’s option, when returned, freight prepaid to CORKEN, INC., 3805 N.W. 36th St., Oklahoma City,
Oklahoma 73112.
Parts subject to wear or abuse, such as mechanical seals, blades, piston rings, valves and packing, and other parts
showing signs of abuse, neglect or failure to be properly maintained are not covered by this limited warranty. Also,
equipment, parts and accessories not manufactured by CORKEN but furnished with CORKEN products are not
covered by this limited warranty and the purchaser must look to the original manufacturer’s warranty, if any. This
limited warranty is void if the CORKEN product has been altered or repaired without the consent of CORKEN.
All implied warranties, including any implied warranty of merchantability or fitness for a particular purpose, are
expressly negated to the extent permitted by law and shall in no event extend beyond the expressed warranty period.
CORKEN DISCLAIMS ANY LIABILITY FOR CONSEQUENTIAL DAMAGES DUE TO BREACH OF ANY WRITTEN OR
IMPLIED WARRANTY ON CORKEN PRODUCTS. Transfer of toxic, dangerous, flammable or explosive substances
using CORKEN products is at the user’s risk. Experienced, trained personnel in compliance with governmental and
industrial safety standards should handle such substances.
Important notes relating to the European Union (EU) Machinery Directive
Pumps delivered without electric motors are not considered as machines in the EU Machinery Directive. These
pumps will be delivered with a Declaration of Incorporation. The fabricator of the machinery must assure and declare
full compliance with this Directive before the machine in which the pump will be incorporated, or of which it is a part,
is put into service.
Contacting the Factory
Before you contact the factory, note the model number and serial number of your pump. The serial number directs
us to a file containing all information on material specifications and test data applying to your specific pump. When
ordering parts, the Corken service manual or Operations, Installation and Maintenance (IOM) manual should be
consulted for the proper part numbers. ALWAYS INCLUDE THE MODEL NUMBER AND SERIAL NUMBER WHEN
ORDERING PARTS.
The model and serial numbers are shown on the nameplate of the unit. Record this information for future reference.
Model No.
Serial No.
Date Purchased
Date Installed
Purchased From
Installed By
2

Table of Contents
Chapter 1—Introduction........................................................................4
1.1 Liquid Transfer By Vapor Differential Pressure ...................................................5
1.2 Residual Vapor Recovery....................................................................5
1.3 Compressor Construction Features ...........................................................6
Chapter 2—Installing Your Corken Compressor....................................................8
2.1 Location .................................................................................8
2.2 Foundation ...............................................................................8
2.3 Piping ...................................................................................8
2.4 Liquid Traps .............................................................................11
2.5 Driver Installation / Flywheels ...............................................................12
2.6. Crankcase Lubrication ....................................................................12
2.7 Relief Valves .............................................................................14
2.8 Truck Mounted Compressors ...............................................................15
2.9 Shutdown/Alarm Devices...................................................................15
Chapter 3—Starting Up Your Corken Compressor.................................................16
3.1 Inspection After Extended Storage ...........................................................16
3.2 Flywheel and V-belt Alignment ..............................................................16
3.3 Crankcase Oil Pressure Adjustment ..........................................................16
3.4 Startup Check List ........................................................................17
Chapter 4—Routine Maintenance Chart .........................................................18
Chapter 5—Routine Service and Repair Procedures...............................................18
5.1 Valves ..................................................................................18
5.2 Heads..................................................................................20
5.3 Piston Rings and Piston Ring Expanders ......................................................20
5.4 Pistons .................................................................................21
5.5 Piston Rod Packing Adjustment .............................................................22
5.6 Cylinder and Packing Replacement ..........................................................22
5.7 Bearing Replacement for Crankcase and Connecting Rod ........................................25
5.7.1 Wrist Pin Bushing Replacement ..........................................................25
5.7.2 Replacing Connecting Rod Bearings ......................................................25
5.7.3 Replacing Crankcase Roller Bearings .....................................................25
5.8 Oil Pump Inspection ......................................................................26
Chapter 6—Extended Storage Procedures .......................................................27
6.1 Repair Kits ..............................................................................27
6.2 Gasket Sets .............................................................................28
Appendices
A. Model Number Identification Code and Available Options..........................................30
B. Specifications ............................................................................32
C. Compressor Selection......................................................................38
D. Outline Dimensions ........................................................................42
E. Parts Details .............................................................................58
Model 91 and F91 .........................................................................58
Model 291 and F291 .......................................................................66
Model 491 and F491 .......................................................................74
Model 691 and F691 .......................................................................82
Model D891 and FD891 ....................................................................90
F. Troubleshooting ...........................................................................98
3

Connections:
Available in threaded NPT or Class 300
RF flanges.
High-efficiency valves:
Valves are quiet and highly durable. Special
suction valves tolerating small amounts of
condensate are available.
O-ring seals:
Easy to install O-ring seals head and cylinder.
Ductile iron construction:
Cylinder and head are made of ductile iron
for maximum thermal shock endurance.
Self-lubricating PTFE piston rings:
State-of-the-art piston ring designs to
provide the most cost-effective operation
of compressors for non-lube service. The
step-cut design provides higher efficiencies
during the entire life of the piston ring.
Positively locked piston:
Simple piston design allows end clearance
to be precisely set to provide maximum
efficiency and long life.
Piston rod seals:
Seals constructed of PTFE incorporating
special fillers to maximize leakage control.
Spring loaded seal design self adjusts to
compensate for normal wear.
Nitrotec
®1 coated piston rods:
Impregnated nitride coating provides
superior corrosion and wear resistance.
Cast-iron crosshead:
Durable cast-iron crossheads provide
superior resistance to corrosion and galling.
Pressure-lubricated crankcase with filter:
Self-reversing oil pump ensures proper
lubrication regardless of directional rotation to
main and connecting rod bearings. Standard
10-micron filter ensures long-lasting bearing
life (not available on Model 91).
1 Registered trademark of TTI Group Ltd.
Chapter 1—Introduction
Construction Details—Model F291 Compressor
4

1.1 Liquid Transfer By Vapor
Differential Pressure
Corken LPG/NH3compressors are designed to transfer
liquefied gases such as butane/propane mixtures
(liquefied petroleum gas or LPG) and Anhydrous Ammonia
(NH3) from one tank to another. Liquefied gases such as
LPG and NH3are stored in closed containers where both
the liquid and vapor phases are present.
Figure 1.1A: Typical nameplate
(also serves as the packing adjusting screw cover)
There is a piping connection between the vapor
sections of the storage tank and the tank being
unloaded, and there is a similar connection between
the liquid sections of the two tanks. If the connections
are opened, the liquid will seek its own level and
then flow will stop; however, by creating a pressure
in the tank being unloaded which is high enough
to overcome pipe friction and any static elevation
difference between the tanks, all the liquid will be
forced into the storage tank (see figure 1.1B). The
gas compressor accomplishes this by withdrawing
vapors from the storage tank, compressing them
and then discharging into the tank being unloaded.
This procedure slightly decreases the storage tank
pressure and increases the pressure in the other tank,
thereby causing the liquid to flow.
The process of compressing the gas also increases the
temperature, which aids in increasing the pressure in the
tank being unloaded.
1.2 Residual Vapor Recovery
The principle of residual vapor recovery is just the
opposite of liquid transfer. After the liquid has been
transferred, the four-way control valve (or alternate
valve manifolding) is reversed so that the vapors are
drawn from the tank just unloaded and discharged into
the receiving tank. Always discharge the recovered
vapors into the liquid section of the receiving tank.
This will allow the hot, compressed vapors to condense,
preventing an undesirable increase in tank pressure (see
figure 1.2A).
Residual vapor recovery is an essential part of the value
of a compressor. There is an economical limit to the
amount of vapors that should be recovered, however.
When the cost of operation equals the price of the
product being recovered, the operation should be
stopped. For most cases in LP-Gas and Anhydrous
Ammonia services, this point is reached in the summer
when the compressor inlet pressure is 40 to 50 psig
Figure 1.1B: Liquid transfer by vapor differential pressure.
Compressor reduces
pressure in storage tank
by removing vapor
Compressor increases
pressure in tank car by
adding vapor
Pressure difference between
tanks causes liquid to flow out of
the tank car into the storage tank
Four Way Valve Position 1
Vapor Line
Vapor Line
Liquid Line
5

Vapor is
bubbled
through liquid
to help cool and
recondense it
Removing vapor from
tank causes liquid heel
to boil into vapor
Liquid line is valved closed
during vapor recovery.
Four Way Valve Position 2
Vapor Line
Vapor Line
Liquid Line
(3.8 to 4.5 bars). A good rule of thumb is not to operate
beyond the point at which the inlet pressure is one-
fourth the discharge pressure. Some liquids are so
expensive that further recovery may be profitable, but
care should be taken that the ratio of absolute discharge
pressure to absolute inlet pressure never exceeds 7 to
1. Further excavation of very high value products would
require a Corken two-stage gas compressor.
Invariably, there is some liquid remaining in the tank
after the liquid transfer operation. This liquid “heel”
must be vaporized before it can be recovered, so
do not expect the pressure to drop immediately.
Actually, more vapor will be recovered during the first
few minutes while this liquid is being vaporized than
during the same period of time later in the operation.
Remember that more than half of the economically
recoverable product is usually recovered during the
first hour of operation on properly sized equipment.
1.3 Compressor
Construction Features
The Corken liquid transfer-vapor recovery compressor
is a vertical single-stage, single-acting reciprocating
compressor designed to handle flammable gases
like LPG and toxic gases such as ammonia. Corken
compressors can handle these potentially dangerous
gases because the LPG/NH3is confined in the
compression chamber and isolated from the crankcase
and the atmosphere. A typical liquid transfer-vapor
recovery compressor package is shown in figure 1.3A.
Figure 1.3A: 107-style compressor mounting.
Corken gas compressors are mounted on oil lubricated
crankcases remaining at atmospheric pressure. Crankshafts
are supported by heavy-duty roller bearings and the
connecting rods ride the crankshaft on journal bearings.
With the exception of the small size model 91 compressor,
all compressor crankcases are lubricated by an automotive
type oil pressure system. An automatically reversible gear
Figure 1.2A: Residual vapor recovery.
6

type oil pump circulates oil through passages in the
crankshaft and connection rod to lubricate the journal
bearings and wrist pins (see figure 1.3B). Sturdy iron
crossheads transmit reciprocating motion to the piston.
Corken’s automatically reversible oil pump design
allows the machine to function smoothly in either
direction of rotation.
Corken compressors use iron pistons locked to the piston
rod. The standard piston ring material is a glass-filled
PTFE polymer specially formulated for non-lubricated
services. Piston ring expanders are placed behind the
rings to ensure that the piston rings seal tightly against
the cylinder wall.
Figure 1.3B: Pressure lubrication system (not available on Model 91).
Piston rod packing is used to seal the gas in the
compression chamber and prevent crankcase oil from
entering the compressor cylinder. The packing consists
of several PTFE V-rings sandwiched between a male and
female packing ring and held in place by a spring (see
figure 1.3C).
The typical Corken compressor valve consists of a seat,
bumper, one or more spring/s and one or more valve/s
discs or plates as shown in figure 1.3D. Special heat-
treated alloys are utilized to prolong life of the valve in
punishing non-lubricated services. The valve opens
whenever the pressure on the seat side exceeds the
pressure on the spring side.
Gasket
Adjusting
screw
Relief ball spring
Relief ball
Suction valve
seat
Valve plate
Spacers
Washer
Spacers
Washer
Valve spring
Suction valve
post
Suction valve
bumper
Valve gasket
Gasket
Bolt
Discharge valve
bumper
Valve spring
Valve plate
Discharge valve
seat
Valve gasket
Suction Valve
Spec 3
Discharge Valve
All Specs
Figure 1.3C: Compressor sealing system
Figure 1.3D: Compressor sealing system
7

Chapter 2—Installing Your Corken
Compressor
2.1 Location
NOTE: Compressor must be installed in a well
ventilated area.
Corken compressors are designed and manufactured
for outdoor duty. For applications where the compressor
will be subjected to extreme conditions for extended
periods such as corrosive environments, arctic
conditions, etc., consult Corken. Check local safety
regulations and building codes to assure installation will
meet local safety standards.
Corken compressors handling toxic or flammable
gases such as LPG/NH3should be located outdoors. A
minimum of 18 inches (457.2 mm) clearance between the
compressor and the nearest wall is advised to make it
accessible from all sides and to provide unrestricted air
flow for adequate cooling.
NOISE. Corken vertical compressors sizes model 91
through 891 should not exceed an 85 DBA noise level at
a distance of one meter (3.3 ft.) when properly installed.
2.2 Foundation
Proper foundations are essential for a smooth running
compression system. The concrete slab should be
at least 8 inches thick with a 2 inch skirt around the
circumference of the baseplate. The total mass of the
foundation should be approximately twice the weight of
the compressor system (compressor, baseplate, motor,
etc.). For Models 91, 291, 491, and 691, the baseplate
should be secured to the foundation using 1/2" diameter
x 12" long “J” bolts. Use 3/4" x 12" anchor bolts for 891.
NOTE: Be sure to use all anchor holes.
Hex nut
Washer
Compressor
baseplate
NOTE: Locate “J” bolts per compressor outline
dimension drawings.
8" minimum
Grout beneath
base
1/2"“J” bolts
12"long
2" minimum
all sides
Concrete foundation
with reinforcements
should be used on
all models
Figure 2.2A: Recommended foundation details for Corken
compressors 91–691.
After leveling and bolting down baseplate and/or skid,
the volume beneath the channel iron baseplate must
be grouted to prevent flexing of the top portion of the
baseplate and the “J” bolt that extends beyond the
foundation. The grout also improves the dampening
capabilities of the foundation by creating a solid interface
between the compressor and foundation.
See ED410: Compressor Foundation Design for more
information.
2.3 Piping
Proper piping design and installation is as important as
the foundation is to smooth operation of the compressor.
Improper piping installation will result in undesirable
transmission of compressor vibration to the piping.
DO NOT SUPPORT PIPING WITH THE COMPRESSOR.
Unsupported piping is the most frequent cause of
vibration of the pipe. The best method to minimize
transmission of vibration from the compressor to the
piping is to use flexible connectors (see figure 2.3A).
Concrete
foundation
Grouted
baseplate
Pipe
support
Pipe
support
Flexible
connections
Flexible
connections
Ground level
Baseplate should
be a maximum
of 4"high
Figure 2.3A: On –107 mountings, the flexible connectors should be
located near the four way valve.
Pipe must be adequately sized to prevent excessive
pressure drop between the suction source and the
compressor as well as between the compressor and the
final discharge point. In most cases, piping should be
at least the same diameter as the suction nozzle on the
compressor. Typically, LPG/NH3liquid transfer systems
should be designed to limit pressure drops to 20 psi (1.4
bar). Appendix C shows recommended pipe sizes for
each compressor for typical LPG/NH3installations.
Care must be taken if a restrictive device such as a valve,
pressure regulator, or back-check valve is to be installed
in the compressor’s suction line. The suction line volume
between the restrictive device and the compressor suction
nozzle must be at least ten times the swept cylinder volume.
See Appendix B for details on cylinder and stroke.
8

107 style compressors are usually connected using a five-
valve (figure 2.3B) or three-valve manifold (figure 2.3C).
The five-valve manifold allows the storage tank to be
both loaded and unloaded. The three-valve manifold only
allows the storage tank to be loaded. Adequate sizing of
the liquid and vapor lines is essential to limit the pressure
drop in the system to a reasonable level (20 psi or less).
The line size helps determine the plant capacity almost
as much as the size of the compressor, and liquid line
sizes are a bigger factor than vapor lines. If the pressure
gauges on the head indicate more than a 15 to 20 psi
(1.0 to 1.4 bars) differential between the inlet and outlet
pressures, the line sizes may be too small or there is too
much piping restriction. The less restriction in the piping,
the better the flow. Appendix C shows recommended
pipe sizes for typical LPG/NH3compressor installation.
A tank car unloading riser should have two liquid hoses
connected to the car liquid valves. If only one liquid
hose is used, the transfer rate will be slower and there
is a good possibility that the car’s excess flow valve
may close.
Since the heat of compression plays an important part in
rapid liquid transfer, the vapor line from the compressor to
the tank car or other unloading container should be buried
or insulated to prevent the loss of heat and the compressor
should be located as near as possible to the tank being
emptied. In extremely cold climates, if the line from the
storage tank to the compressor is over 15 feet (4.6 meters)
long, it should be insulated to lessen the possibility of
vapors condensing as they flow to the compressor. The
vapor recovery discharge line should not be insulated.
Placing the compressor as close as possible to the tank
Hydrostatic relief valve Back check valve
Relief valve
4-Way valve
C
Vapor line to liquid phase
in storage tank
B
Vapor line to truck
trailer or tank
(local transport)
Vapor line to
rail car
(inbound bulk
transport)
Vapor line to gas phase
in storage tank
D
E
A
Bury or
insulate in
cold climate
areas
4-Way Valve
Position 1
E B
D A C
4-Way Valve
Position 2
Service to Perform Valve Position
4-way A B C D E
1. Unload tank car
into storage tank
Position
One Open Open Close Close Close
2. Recover vapors
from tank car into
storage tank
Position
Two Close Open Open Close Close
3. Unload transport
or truck into
storage tank
Position
One Open Close Close Close Open
4. Recover vapors
from transport or
truck into storage
tank
Position
Two Close Close Open Close Open
5. Load truck or
field tank from
storage tank
Position
Two Open Close Close Close Open
6. Load truck or field
tank from tank car
Position
One Close Open Close Open Close
7. Equalize between
tank car and
storage tank
without using
vapor pump
—Open Open Close Open Open
8. Equalize between
truck or field tank
and storage tank
without using
vapor pump
—Open Close Close Open Close
4-way Valve Operation
Figure 2.3B: Five valve manifold piping system.
9

being unloaded will minimize heat loss from the discharge
line for the best liquid transfer rate.
Unloading stationary tanks with a compressor is quite
practical. Delivery trucks and other large containers can
be filled rapidly if the vapor system of the tank to be
filled will permit fast vapor withdrawal, and if the liquid
piping system is large enough. Many older trucks (and
some new ones) are not originally equipped with vapor
excess flow valves large enough to do a good job and
these should be replaced by a suitable size valve. The
liquid discharge should be connected to the tank truck
pump inlet line rather than the often oversized filler valve
connection in the tank head.
It is of extreme importance to prevent the entry of
liquid into the compressor. The inlet of the compressor
should be protected from liquid entry by a liquid trap
(see section 2.4). It is of equal importance to protect the
discharge of the compressor from liquid. This may be
done by installing a check valve on the discharge and
designing the piping so liquid cannot gravity-drain back
into the compressor. Make sure to install a check valve
on vapor lines discharging to the liquid space of the tank.
All piping must be in accordance with the laws and codes
governing the service. In the United States, the following
codes apply:
For LP-Gas — The National Fire Protection Association
Pamphlet No. 58, Standard for the Storage and Handling
of Liquefied Petroleum Gases.
For Ammonia — The American National Standards
Institute, Inc., K61.1-1999, Storage and Handling of
Anhydrous Ammonia.
Back check valve
Hydrostatic releif valve
A
B
C
Vapor line rail car
(in-bound
bulk transfer)
Bury or insulate in
cold climate areas
4-Way valve
Relief valve
Vapor line to gas
phase in storage
Vapor line to liquid
phase in storage
4-Way Valve
Position 1
B
A C
4-Way Valve
Position 2
Service to
Perform
Valve Position
4-way A B C
1. Unload
tank car into
storage tank
Position
One Open Open Close
2. Recover
vapors from
tank car into
storage tank
Position
Two Close Open Open
4-way Valve Operation
Figure 2.3C: Three valve manifold piping system.
10