Deno L2-20 Starting Air Compressor Spare Parts

Deno L2-20 is a two-stage, air-cooled, single-acting starting air compressor used to start marine and shore-based diesel engines and to feed general high-pressure air systems. Harbor Eagle supplies the full range of consumable and service parts to keep an L2-20 in class — matched by part number, quoted quickly, and shipped to the vessel or workshop.

Which Deno L2-20 parts wear first?

On a starting air compressor, the parts that come up most often in a service or overhaul are the air-side wear items: the concentric valve assemblies (plates and springs), the piston rings and oil rings, the air filter element, and the full set of gaskets and O-rings disturbed every time a cylinder head comes off. The manufacturer's schedule recommends replacing valve springs at roughly 2,000 running hours (even if they don't look worn), checking valve plates for flatness — the wear limit is 6% of original plate thickness — and never re-using the aluminium head gasket.

Fast movers to keep on the shelf: Air filter element 8801A · 1st-stage valve group 7100A · 2nd-stage valve group 7200A · 1st-stage piston rings 2102B / 2103B · 2nd-stage piston rings 2202A / 2203A · LP safety valve 7500A · HP safety valve 7600A · coupling rubber set 8705A.

Deno L2-20 spare parts — part number reference

Search by the part number stamped in the L2-20 parts list, or by component name. Every number below can be quoted individually or as a service kit. If you have a number that is not listed, send it — the L2-20 shares many fittings and fasteners across groups.

Concentric valves — 1st stage (assembly 7100A)

Part No.	Component	Function & notes
7100A	Concentric valve group, 1st stage	Complete LP valve assembly
7101A	Valve seat	LP concentric valve
7102A	Valve guard	LP concentric valve
7103A	Suction valve plate (small)	Wear part
7104A	Suction valve spring (small)	Replace as a set at ~2,000 h
7105A	Suction valve plate (large)	Wear part
7106A	Suction valve spring (large)	Replace as a set
7107A	Delivery valve plate	Wear part
7108A	Delivery valve spring	Replace as a set
7109A	Valve clamping bolt
7110A	Valve clamping nut

Concentric valves — 2nd stage (assembly 7200A)

Part No.	Component	Function & notes
7200A	Concentric valve group, 2nd stage	Complete HP valve assembly
7201A	Valve seat	HP concentric valve
7202A	Valve guard	HP concentric valve
7203A	Suction valve plate (small)	Wear part
7204A	Suction valve spring (small)	Replace as a set
7205A	Delivery valve plate	Wear part
7206A	Delivery valve spring	Replace as a set
7207A	Valve clamping bolt
7208A	Valve clamping nut

Pistons, rings & connecting rods

Part No.	Component	Function & notes
2101B	Piston, 1st stage (LP)	Light aluminium alloy
2102B	Piston ring, 1st stage	Compression ring — wear part
2103B	Piston oil ring, 1st stage	Oil scraper — wear part
2104A	Piston pin, 1st stage
2105A	Snap ring, 1st stage
2201A	Piston, 2nd stage (HP)	Cast iron
2202A	Piston ring, 2nd stage	Compression ring — wear part
2203A	Piston oil ring, 2nd stage	Oil scraper — wear part
2204A	Piston pin, 2nd stage
2205A	Snap ring, 2nd stage
4101A	Connecting rod, 1st stage (set)	Upper/lower — supplied as set 4101A
4201A	Connecting rod, 2nd stage (set)	Upper/lower — supplied as set 4201A
4102A	Crank pin metal / big-end bearing (set)	Upper & lower shells
4103A	Piston pin bush, 1st stage	Phosphor bronze
4203A	Piston pin bush, 2nd stage	Phosphor bronze

Cylinders, heads, gaskets & O-rings

Part No.	Component	Function & notes
1101B	LP cylinder head	1st stage
1102A	Gasket ring, LP head	Do not re-use — renew on assembly
1103A	Head packing, LP	Renew on assembly
3101B	Cylinder, 1st stage	100 mm bore
3102A	O-ring, cylinder	Common LP/HP — renew on assembly
1201A	HP cylinder head	2nd stage
1202A	Gasket ring, HP head	Do not re-use — renew on assembly
1203A	Head packing, HP	Renew on assembly
3201B	Cylinder, 2nd stage	45 mm bore

Crankcase, crankshaft & bearings

Part No.	Component	Function & notes
D6101A	Crank case
5101B	Crank shaft
6308A	Main bearing	2 off
6121A	Oil seal	2 off — renew on assembly
6122A	Main bearing case O-ring
6132A	Main bearing cover O-ring
6106A	Oil level gauge (sight glass)

Safety valves, non-return valve, drain separators & coupling

Part No.	Component	Function & notes
7500A	LP safety valve, complete	1st stage, ~8 bar
7600A	HP safety valve, complete	2nd stage, ~31 bar
8210A	Non-return valve, complete	Delivery — available as full set
8212A	Non-return valve element	Wear part
8215A	Seat O-ring, non-return
D8101C	Drain separator body, 1st stage
D8201B	Drain separator body, 2nd stage
9211A	Needle valve (drain)
8701A	Coupling, compressor side	Flexible coupling
8703B	Coupling, motor side	Flexible coupling
8705A	Coupling rubber set	Bolts, washers & rubbers — wear set
7013A	Vibration damper	Anti-vibration mount

Air filter & cooler

Part No.	Component	Function & notes
8801A	Air filter element	Fast-moving consumable (set 8800B)
8800B	Air filter, complete set	Element + both cases
8550B	Fan	Axial cooling fan
D8510A	LP cooler pipe	Supplied with 2 flare nuts
D8556A	Fan cover

Service data at a glance

Item	Value
Type	2-stage, air-cooled, single acting
Cylinder bore	1st stage 100 mm · 2nd stage 45 mm
Stroke	42 mm
Design pressure	33 kg/cm² (≈32 bar)
Safety valve set — LP / HP	8 ±1 bar / 31 ±1 bar
Crankcase oil quantity	1.8 L (replenish line 0.6 L)
First oil change	After 50 running hours, then every 600 hours
Valve spring replacement	~ every 2,000 running hours
Valve plate wear limit	6% of original thickness
Overhaul interval	Once every 2 years

Torque settings (N·m)

Connection	Torque
Cylinder heads	40.0 – 44.5
Connecting rods	70.0 – 74.5
1st stage valve	25.0 – 29.5
2nd stage valve	15.0 – 17.0
Vibration dampers	40.0 – 44.5

Frequently asked questions

What spare parts does a Deno L2-20 compressor need most often?

The most frequently replaced Deno L2-20 parts are the concentric valve plates and springs (assemblies 7100A and 7200A), piston rings and oil rings (2102B/2103B and 2202A/2203A), the air filter element 8801A, and the gaskets and O-rings disturbed during head removal. Valve springs are typically renewed as a full set around every 2,000 running hours.

What is the oil change interval for a Deno L2-20?

Change the oil after the first 50 running hours, then every 600 running hours. Check oil level and condition daily. Crankcase capacity is about 1.8 litres; use a good-quality compressor oil (SAE 20/30 grade depending on ambient temperature and daily running hours).

What are the safety valve set pressures on the L2-20?

The 1st-stage (LP) safety valve is set to 8 ±1 bar and the 2nd-stage (HP) safety valve to 31 ±1 bar. Complete safety valves are available under 7500A (LP) and 7600A (HP), and performance should be checked monthly.

How do I know when a valve plate needs replacing?

Check valve plates for flatness; the maximum wear limit is 6% of the original plate thickness. Never re-use grooved plates, replace all springs in a valve at the same time, and always renew the aluminium head gasket.

Can Harbor Eagle supply a complete valve or overhaul kit rather than single parts?

Yes. Beyond single part numbers, we quote complete valve assemblies (7100A / 7200A), the air filter set 8800B, big-end bearing sets (4102A), connecting-rod sets (4101A / 4201A) and made-to-order gasket and O-ring overhaul kits. Send your compressor serial and running hours and we will scope the kit to the job.

Send us the part number — get a quote back fast

One list, one contact, worldwide delivery to vessel or workshop. Whether it's a single air filter element or a full 2-year overhaul kit for a Deno L2-20, Harbor Eagle turns your part numbers into a priced, deliverable offer. Request a quote or email marketing@harboreagle.com.

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Harbor Eagle is an independent supplier of marine spare parts and is not affiliated with, authorised by, or endorsed by Deno Compressors B.V. "Deno" and "L2-20" are used only to identify the equipment these parts fit and are the trademarks of their respective owners. Part numbers are listed for cross-reference to help buyers identify the correct component.