1 09/97 CB-257

1
LB161 LPG / NH3 Compressor
This presentation is a simplified description of
the disassembly of a Blackmer LB161. The current
production model is the LB161B (August 1997).
The largest difference affecting disassembly is
in the oil pump. The current oil pump is self
reversing and is not shown in this
presentation Select one of the following
Hilites Only
Detailed Text
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LB161 LPG / NH3 Compressor
3
LB161 LPG / NH3 Compressor

• The LB161 compressor is suitable for many
  applications, but the most common is the transfer
  and vapor recovery of liquefied gases such as
  propane, butane, and anhydrous ammonia. The
  non-lubricated cylinder design of the LB161
  allows the transfer of these products without
  contamination of the products and is capable of
  transferring up to 90 gallons per minute (340
  lpm). Typically the LB161 is driven by a 5 or
  7.5 HP driver in the 650 to 800 rpm range.

4
LITERATURE

• Be sure you have the proper literature before
  starting work on the compressor. Locate the
  parts list and Installation, Operation and
  Maintenance instructions. In addition, you may
  have received additional instruction sheets with
  your machine that further describe such items as
  valves and packing.
• Literature is available on the web at
• blackmercompressor.com
• or from your Blackmer distributor.

5
Tools

• The tools normally required for small machine
  service will be adequate. A small strap wrench
  is useful as well as a good spanner. The Blackmer
  spanner p/n 790316 has 1/4 pins and is used for
  piston removal. Blackmer wrench p/n 790535 may
  be used for the valve hold down screws. A flat
  scraper and inside snap ring pliers are also
  needed.
• Blackmer offers a complete tool kit which has all
  of the hand tools necessary to dismantle the
  machine.
• On larger machines a small hoist might be needed
  for one man to do the job, depending on the
  environment. Generally, two men can handle the
  disassembly of any Blackmer machine.

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Nameplate

• On the side of every Blackmer compressor is a
  nameplate which doubles as an access opening for
  inspecting the piston rod.
• The nameplate will show the compressors model
  number, serial number, ID number, and oil
  capacity.
• The compressor ID is a coded number that fully
  describes the compressors construction.
• Make certain that you have these identifying
  numbers when you call your Blackmer distributor
  for parts or service assistance.

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LB161 Compressor

• Blackmer offers a variety of LPG transfer
  compressors.
• The LB162 is similar to the LB161 shown in this
  presentation but has two seals separated by a
  distance piece on each piston rod.
• Larger models are
• LB361 / LB362 15 bhp (11 kw)
• LB601 / LB602 40 bhp (30 kw)
• LB942 50 bhp (37 kw)

8
Pressure Gauges

• Blackmer compressors are typically fitted with a
  pressure gauge on both the suction and discharge.
  The gauges are fitted with a pulsation dampener
  to eliminate much of the vibration of the gauge
  needle making it easier to read and extending the
  life of the pressure gauge.
• Both suction and discharge pressure gauges should
  be installed on every compressor.

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Valve Caps and Hold Down Screws

• Remove the valve caps to access the valves.
• After the valve caps have been removed, the
  valve hold down screws can be removed with a
  spanner wrench (such as a Blackmer p/n 790316 or
  790535).
• Note the O-ring under each cap these should be
  replaced rather than reused. Older models will
  have a metal gasket instead of an O-ring under
  the valve cap.

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Valves

• With the hold down screws removed, the valve
  post, valve and gasket may be taken out.
• A liquid relief device in the suction valve post
  helps protect the compressor in case liquid
  enters the cylinder area. It consists of a ball
  and spring relief valve which will allow liquid
  to be returned to the suction piping if
  necessary.
• The discharge valve is held in place by a solid
  post.
• Make certain the valve gaskets are removed with
  each valve as they may be difficult to see in the
  head. The valve gaskets are normally aluminum
  and must be replaced when the valves are removed.

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Cylinder Head

• To remove the cylinder head, unbolt the two
  center head bolts from the top of the head and
  the four head bolts from the corners of the head.
  The two center head bolts have metal gaskets
  which are normally not reusable. After the
  cylinder head bolts have been removed, the head
  may be lifted from the cylinder.

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Head O-rings and Piston Nut

• The head is sealed to the cylinder with four
  O-rings (usually Buna-N). O-rings seal each
  cylinder and both center head bolts and are not
  normally reusable.
• The piston nut is removed with an adjustable
  spanner. This spanner has two 1/4 pins which
  fit into holes in the top of the piston nut. Note
  the nylon locking device on the piston nut.

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Piston Removal

• Once the piston nut has been removed, the spanner
  is used to unscrew the piston from the rod.
  Under each piston is a thick washer and one, or
  more, shims. These shims adjust the height of
  the piston in the cylinder. This is referred to
  as the deck height. Unless a major part has
  been changed, the deck height should not need
  adjustment. Changing the piston, crosshead
  assembly, cylinder body, main bearings or
  crankshaft may require adjustment of the deck
  height.
• Rotate the crankshaft to bring the other piston
  to top-dead-center for removal. Each piston is
  fitted with three piston rings. Each ring has a
  stainless steel expander between it and the
  piston. Install each piston ring with the bevel
  on the inside facing up. The ring and expander
  gaps should be staggered at 180 intervals during
  installation.

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Cylinder

• With the pistons removed, the cylinder can be
  unbolted and removed to gain access to the
  packing boxes. Two O-rings seal the bottom of the
  cylinder.
• Notice the passage in the bottom of the cylinder
  between the bores. This allows gas to move from
  one cylinder to the other as the pistons move up
  and down.

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Packing Box Removal

• The packing boxes are secured by a hold down
  screw which is removed with the same adjustable
  spanner that was used on the piston nut and
  piston. Note that the hold down screw also has a
  nylon insert that keeps it in place.
• The packing boxes may now be lifted off the rod.
  O-rings seal the bottom side of the packing boxes.

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Packing Box disassembly

• To remove the seals (packing) from the box
• Remove the top snap ring with a pair of inside
  snap ring pliers. Depress the spring with a
  screwdriver handle to make this operation easier.

17
Rod Seals

• With the snap ring removed, the top washer,
  spring, middle washer, seal rings, bottom washer
  and retainer ring can all be removed.
• The seal consists of three types of rings. One
  ring is a male ring, next a series of V-rings,
  then a female ring.
• On LB161 compressors, the spring and male ring
  will be at the top and the female ring will be at
  the bottom.

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Piston Rod Inspection

• The piston rods and the top on the crossheads are
  visible through the opening when the nameplate is
  removed.
• The crosshead guide is secured to the crankcase
  by six bolts.

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Crankcase and Crosshead

• With the crosshead guide removed, the crosshead /
  piston rods are visible. The flat gasket on top
  of the crankcase may require the use of a flat
  scraper to remove completely.
• The oil dipstick is located in the access cover.
  On current models, it is located adjacent to the
  access cover. The oil viscosity and capacity are
  found in the Instruction Manual.

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Crosshead Connecting Rod Removal

• Removal of the crankcase access cover and gasket
  permits access to the connecting rods. After the
  bottom cap of the connecting rod has been
  removed, the piston rod / crosshead and the top
  half of the connecting rod may be lifted off from
  above.

21
Crosshead and Connecting Rod

• The connecting rod and crosshead assembly are
  separated by removing the wrist pin in a bench
  press. Note that the wrist pin has a plastic
  retainer plug on each end.
• The piston rod is permanently secured to the
  crosshead at the factory and no attempt should be
  made to separate them. Final machining is done to
  the assembled crosshead / rod which precludes
  their reassembly once separated. The grooves in
  the crosshead are lubrication channels.
• The small end of the connecting rod has a bronze
  bushing and is lubricated via and internal port
  running the length of the connecting rod.

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Crosshead and Connecting Rod (contd)

• A precision insert split shell bearing is located
  at the big journal end. Tabs on the bearing
  shells fit into slots in the rod and bearing cap.
  These retain the shells and align the oil feed
  holes.
• The LB161 uses a bronze bushing on a steel wrist
  pin at the small end of the conrod. The oil
  admission hole in the bearing or bushing must
  align with the oil supply hole in the connecting
  rod small end. When the bronze wrist pin
  bushing is replaced, it must be honed to final
  dimension after being pressed into the connecting
  rod
• The rod and cap are matched sets, do not mix.
  Match marks must align when assembling bearing
  cap to connecting rod.

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Oil Pressure adjustment, Strainer

• The oil pressure adjustment screw includes an
  O-ring, lock nut, spring and ball. Turn the
  screw inward (clockwise) to increase the oil
  pressure setting.
• The oil pickup tube with washers, O-ring and
  strainer fits in the crankcase under the bearing
  carrier. If any foreign material is noticed in
  the strainer, its source should be quickly
  identified to prevent reoccurrence of the
  problem.
• The pipe plug next to the oil pickup tube opening
  is the crankcase oil drain.
• Some units will be fitted with an external oil
  filter (not shown).

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Oil Pump

• This photo shows the oil pump used in the LB161.
  The LB161B uses a different pump.
• Remove the oil pump cover and O-ring to withdraw
  the oil pump. Notice the small O-ring on the
  pump shaft and the bronze bushing in the bearing
  carrier.
• The oil pump cover can be installed with either
  left or right rotation arrow visible. When
  installing the cover, make sure that the arrow at
  the TOP of the cover indicates the desired
  rotation direction.

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Bearing Carrier

• The photo shows the bearing carrier / oil pump
  used in the LB161. The LB161B uses a different
  style.
• The entire bearing carrier / oil pump assembly,
  with gasket, can be removed intact. This allows
  the crankshaft to be removed.
• Note the slot in the end of the oil pump drive
  shaft. This slot must align with the drive tang
  in the end of the crankshaft during installation.

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Crankshaft Removal

• Remove the crosshead and connecting rod
  assemblies to proceed with the crankshaft
  removal. Notice the lubrication holes on the
  bearing journals. Also note the spray nozzles on
  the crankshaft. The spray nozzles lubricate the
  crosshead guide and the main roller bearings.
  
• The top of the crankcase is fitted with a
  breather which prevents entry of foreign material
  into the crankcase but allows the release of
  crankcase pressure.

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Bearing Cover Plate

• The bearing cover plate is on the flywheel side
  of the crankcase. Behind this plate are a series
  of shims which adjust the preload on the main
  bearings. These shims are normally reusable and
  the shim thickness will not have to be adjusted
  unless the crankshaft and / or main bearings are
  replaced. The bearing cover plate also contains
  a crankshaft oil seal.

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End ofPresentation
1809 Century Avenue Grand Rapids, MI, USA
49503 Ph 616-241-1611 Fax [phone] www.black
mer.com
29
LB161 LPG / NH3 Compressor
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LB161 LPG / NH3 Compressor

• Liquid transfer / vapor recovery of
• propane
• butane
• anhydrous ammonia
• Transfer without contamination
• Up to 90 GPM
• (340 lpm)
• Usually driven by 5 or 7.5 HP driver at 650 to
  800 rpm

31
LITERATURE

• Have the proper literature at hand
• Parts lists
• Installation, Operation and Maintenance manual
• For literature
• blackmercompressor.com
• Call your Blackmer distributor

32
Tools

• Use standard tools for small machines
• Blackmer adjustable spanner with 1/4 pins (p/n
  790316)
• Blackmer valve hold down screw wrench (790535)
• Inside snap ring pliers
• Blackmer tool kit available

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Nameplate

• Model number
• Serial number
• I.D. number
• Defines construction
• Oil capacity
• Rod inspection access

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LB161 Compressor

• Other Models Available
• LB162 double-seal
• LB361 / LB36215 bhp (11 kw)
• LB601 / LB60240 bhp (30 kw)
• LB942 50 bhp (37 kw)

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Pressure Gauges

• Always install!
• Suction Discharge
• Pulsation dampener- extends gauge life makes it
  easier to read.

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Valve Caps and Hold Down Screws

• Cap O-ring (or metal gasket)
• Screws are removed with spanner

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Valves

• Liquid relief device - ball spring
• Post
• Valves
• Valve gaskets - usually aluminum
• Always replace gaskets

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Cylinder Head

• Two center head bolts have metal gaskets

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Head O-rings and Piston Nut

• Head O-rings - not normally reusable
• Remove piston nut with 1/4 pin spanner
• Piston nut has nylon locking insert

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Piston Removal

• Use spanner to unscrew piston
• Washer and shims adjust piston deck height
• Piston rings have expanders
• Bevel on inside of the ring faces up
• Install rings and expanders with staggered gaps

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Cylinder

• Two O-rings seal the cylinder to the crankcase
• Under-piston channel between bores

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Packing Box Removal

• Remove hold down screw with spanner
• Hold down screw has nylon locking insert
• O-rings seal bottom of packing box

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Packing Box disassembly

• Depress spring with screwdriver
• Remove retainer ring with inside snap ring pliers

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Rod Seals

• Female packing ring on bottom
• V - ring type
• Male packing ring on top
• Spring is on top of the packing

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Piston Rod Inspection

• Piston rods and tops of the crossheads are
  visible through the nameplate opening

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Crankcase and Crossheads

• Gasket between crankcase and guide
• Oil level dipstick

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Crosshead Connecting Rod Removal

• Access cover and gasket
• Remove lower bearing caps, lift crosshead and
  connecting rod assembly

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Crosshead and Connecting Rod

• Plastic retainer plugs
• Connecting rod has cast-in oil channel, big end
  to small end
• Connecting rod is Ductile Iron
• Cast iron crosshead
• Dont remove piston rod from crosshead

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Crosshead and Connecting Rod (contd)

• Wrist pin is pressed into the crosshead
• Wrist pin bushing is pressed in and honed to the
  proper bore
• Bushing oil hole must align with connecting rod
  feed hole
• Split bearings on the crankend
• Keep rod caps on the correct rod - use match marks

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Oil Pressure adjustment, Strainer

• Oil pressure adjustment screw and lock nut
• Clean the oil strainer
• Oil drain plug
• External oil filter on some units

51
Oil Pump

• May be installed for either rotation direction
• The top arrow indicates rotation direction
• Rotate cover 180 for opposite rotation direction

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Bearing Carrier

• Carrier and oil pump are removed as an assembly
• Slot in carrier fits into tang at crankshaft end

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Crankshaft Removal

• Pressure lubrication holes at the journal
  bearings
• Oil spray nozzles on the crankshaft for the
  crossheads
• Crankcase breather vent

54
Bearing Cover Plate

• Located at flywheel end
• Shims adjust main bearing preload
• Cover contains crankshaft oil seal

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End ofPresentation
1809 Century Avenue Grand Rapids, MI, USA
49503 Ph 616-241-1611 Fax [phone] www.black
mer.com