1. Select one of the following:
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

2. LB161 LPG / NH3 Compressor
These slides give a simplified description of the disassembly of a Blackmer HD372A.
The current production model is HD372C. Significant changes are needle bearings at the wrist pin, a larger wrist pin [ 1” instead of 7/8”] and a full-flow, spin-on, oil filter as standard equipment.
With some unimportant differences, this presentation is also appropriate for the other Blackmer 1 and 2 stage models, with the exception of the HD942, double-acting 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.
Be sure that you have the literature you require before starting to 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.
If you do not have all of the necessary information, call your Blackmer distributor

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 has 1/4” pins and is used for piston removal. Blackmer wrench p/n 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.

6. 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 compressor’s model number, serial number, ID number, and oil capacity.
The compressor ID is a coded number that fully describes the compressor’s construction.
Make certain that you have these identifying numbers when you call your Blackmer distributor for parts or service assistance.
Nameplate

7. 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)]
LB [50 bhp (37 kw)]
Blackmer offers a variety of two-stage compressors.
The HDL372 is similar to the HD372 shown in this presentation but is liquid cooled. It has a water cooled head and cylinder for lower metal temperatures and longer life of wearing parts. It is also fitted with a water cooled intercooler to keep gas temperatures at acceptable levels for continuous duty.
The smaller HD172 air-cooled model is rated for 10 bhp (7.5 kw).
The larger HD612 (air-cooled) and HDL612 (liquid cooled) models are rated for 40 bhp (30 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.

9. 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 or ).
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.

10. 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.

11. 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.

12. 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.

13. 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.

14. 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.

15. 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.

16. 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.

18. 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.

19. 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.

20. 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.

22. Crosshead and Connecting Rod (cont’d)
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.

23. 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).

24. 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.

25. 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.

26. 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.

27. 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. x

28. End of Presentation 1809 Century Avenue Grand Rapids, MI, USA 49503
Ph:
Fax:
These slides give a simplified description of the disassembly of a Blackmer HD372A.
The current production model is HD372C. Significant changes are needle bearings at the wrist pin, a larger wrist pin [ 1” instead of 7/8”] and a full-flow, spin-on, oil filter as standard equipment.
With some unimportant differences, this presentation is also appropriate for the other Blackmer 1 and 2 stage models, with the exception of the HD942, double-acting compressor.

29. LB161 LPG / NH3 Compressor
These slides give a simplified description of the disassembly of a Blackmer HD372A.
The current production model is HD372C. Significant changes are needle bearings at the wrist pin, a larger wrist pin [ 1” instead of 7/8”] and a full-flow, spin-on, oil filter as standard equipment.
With some unimportant differences, this presentation is also appropriate for the other Blackmer 1 and 2 stage models, with the exception of the HD942, double-acting compressor.

30. 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
Be sure that you have the literature you require before starting to 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.
If you do not have all of the necessary information, call your Blackmer distributor

31. LITERATURE Have the proper literature at hand Parts lists
Installation, Operation and Maintenance manual
For literature:
blackmercompressor.com
Call your Blackmer distributor
Be sure that you have the literature you require before starting to 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.
If you do not have all of the necessary information, call your Blackmer distributor

32. Tools Use standard tools for small machines
Blackmer adjustable spanner with 1/4” pins (p/n )
Blackmer valve hold down screw wrench (790535)
Inside snap ring pliers
Blackmer tool kit available
Blackmer offers a complete tool kit which has all of the hand tools necessary to dismantle the machine.
The tools normally required for small machine service will be adequate for the work on an HD compressor. A small strap wrench is useful and a good spanner. The Blackmer p/n spanner is used for valve hold down screws. The Blackmer spanner p/n has 1/4” pins and is used for piston removal. A flat scraper and inside snap ring pliers are also needed.
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.

33. Nameplate Model number Serial number I.D. number Oil capacity
Defines construction
Oil capacity
Rod inspection access
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 compressor’s model number, serial number, ID number, and oil capacity.
The compressor ID is a coded number that fully describes the compressor’s construction.
Make certain that you have these identifying numbers when you call your Blackmer distributor for parts or service assistance.

34. LB161 Compressor Other Models Available: LB162 double-seal
LB361 / LB362 [15 bhp (11 kw)]
LB601 / LB602 [40 bhp (30 kw)]
LB942 [50 bhp (37 kw)]
Blackmer offers a variety of two-stage compressors.
The HDL372 is similar to the HD372 shown in this presentation but is liquid cooled. It has a water cooled head and cylinder for lower metal temperatures and longer life of wearing parts. It is also fitted with a water cooled intercooler to keep gas temperatures at acceptable levels for continuous duty.
The smaller HD172 air-cooled model is rated for 10 bhp (7.5 kw).
The larger HD612 (air-cooled) and HDL612 (liquid cooled) models are rated for 40 bhp (30 kw).

35. Pressure Gauges Always install! Suction & Discharge
Pulsation dampener- extends gauge life & makes it easier to read.
Optional suction valve unloaders allow the compressor to be deactivated in service. That is, gas that is drawn into the cylinder during the suction stroke is expelled through the suction valve on the discharge stroke and does not pas through the machine into the discharge line. This is accomplished by holding the compressor suction valve plates open throughout the full cycle. The unloader mechanism does this mechanically and can be powered by compressed gas from the discharge storage or an independent source, as required.
The suction valves can be unloaded to produce no-load starts or reduced capacity operation on demand.

36. Valve Caps and Hold Down Screws
Cap O-ring (or metal gasket)
Screws are removed with spanner
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 ).
To prevent possible damage to the valves during reassembly, the hold down screws must be completely removed from the valve cover plates.
Note the O-ring under each cap; these should be replaced rather than reused. The compressor I.D. number on the nameplate contains a code for the O-ring material used

37. Valves Liquid relief device - ball & spring Post Valves
Valve gaskets - usually aluminum
Always replace gaskets
Once the cover plates removed, the valve cage, valve and gasket may be taken out.
Make certain the valve gaskets are removed with each valve. When they are left in the head they may be difficult to see. The valve gaskets are normally iron although other materials are used as required. Valve gaskets should be replaced when the valves are removed.

38. Cylinder Head Two center head bolts have metal gaskets
To remove the cylinder head, unbolt the two center head bolts from the top of the head and the eight head bolts from the bottom of the head. After the cylinder head bolts have been removed, the head may be lifted from the cylinder. Note that the head is sealed to the cylinder by an O-ring at each cylinder bore.

39. 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
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.
Once the piston nut has been removed, the same spanner can be used to unscrew the piston from the rod. There is a thick washer under each piston 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. Change of 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.

40. 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
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.
Once the piston nut has been removed, the same spanner can be used to unscrew the piston from the rod. There is a thick washer under each piston 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. Change of 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.

41. Cylinder Two O-rings seal the cylinder to the crankcase
Under-piston channel between bores
When installing he piston rings and expanders make sure that each piston ring is installed with its gap 1800 from the expander gap. Also, the piston ring gaps should be staggered around the piston.
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.

42. Packing Box Removal Remove hold down screw with spanner
Hold down screw has nylon locking insert
O-rings seal bottom of packing box
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 top and bottom side of the packing boxes.

43. Packing Box disassembly
Depress spring with screwdriver
Remove retainer ring with inside snap ring pliers
Remove the seals ( packing ) from the box as follows.
Use a pair of inside snap ring pliers to remove the top snap ring. A screwdriver handle can be used to depress the spring to make this operation easier.
Turn the packing box over to remove the bottom seal.

44. Rod Seals Female packing ring on bottom “V” - ring type
Male packing ring on top
Spring is on top of the packing
With the snap ring removed, the top washer, the spring, the middle washer, the seal, the 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.
The upper and lower seals are the same. The seal orientation will depend on the operating pressures. The spring and washer, however, always press against the male ring.
The red oil deflector ring fits on the piston rod between the two seals. The holes in the side of the packing box allow the oil deflector ring to be guided onto the rod as the box is installed.

45. Piston Rod Inspection
Piston rods and tops of the crossheads are visible through the nameplate opening
The piston rods and the top on the crossheads are visible through the opening when the nameplate is removed

46. Crankcase and Crossheads
Gasket between crankcase and guide
Oil level dipstick
By removing the crosshead guide, access is given to the crosshead / piston rods.
The flat gasket that fits on top of the crankcase may require the use of a flat scraper to remove completely.

47. Crosshead & Connecting Rod Removal
Access cover and gasket
Remove lower bearing caps, lift crosshead and connecting rod assembly
The oil dipstick is located adjacent to the access cover. In earlier models, it was located in the access cover. The oil viscosity and capacity are found in the Instruction Manual.
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.

48. 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
Don’t remove piston rod from crosshead
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 shown here has a bronze bushing. This is used on some models. Current production for the HD362, 342 and 372 incorporates a steel needle bearing in the connecting rod small end.

49. Crosshead and Connecting Rod (cont’d)
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
The ductile iron connecting rod has a cast in tube to route oil from the big end to the wrist pin.
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 feeds.
The HD372A uses a bronze bushing on a steel wrist pin at the small end of the conrod. A steel needle bearing is used on some models. 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.

50. Oil Pressure adjustment, Strainer
Oil pressure adjustment screw and lock nut
Clean the oil strainer
Oil drain plug
External oil filter on some units
The oil pressure adjustment screw complete with O-ring, lock nut, spring and ball fits into the bearing carrier. Turning the screw inward (clockwise) increases 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.

51. Oil Pump May be installed for either rotation direction
The top arrow indicates rotation direction
Rotate cover 180° for opposite rotation direction
This photo shows the oil pump used in the HD372A. Models HD372B and HD372C use 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.

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

53. Crankshaft Removal Pressure lubrication holes at the journal bearings
Oil spray nozzles on the crankshaft for the crossheads
Crankcase breather vent
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.

54. Bearing Cover Plate Located at flywheel end
Shims adjust main bearing preload
Cover contains crankshaft oil seal
The bearing plate cover is on the flywheel side of the crankcase. Behind this plate are 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 or main bearings are replaced.
The bearing cover plate also contains a crankshaft oil seal.

55. End of Presentation 1809 Century Avenue Grand Rapids, MI, USA 49503
Ph:
Fax:
These slides give a simplified description of the disassembly of a Blackmer HD372A.
The current production model is HD372C. Significant changes are needle bearings at the wrist pin, a larger wrist pin [ 1” instead of 7/8”] and a full-flow, spin-on, oil filter as standard equipment.
With some unimportant differences, this presentation is also appropriate for the other Blackmer 1 and 2 stage models, with the exception of the HD942, double-acting compressor.