Carrier 5H Compressor Cylinder Head

Carrier Compressor 5H40, 5H60, 5H80, 5H120 Cylinder Head

This heavy-duty cylinder head is manufactured to OEM design tolerances for the open-drive Carrier / Carlyle 5H Series reciprocating compressors. The 5H series utilizes modular cylinder groupings (2 cylinders per head/bank) across 4-, 6-, 8-, and 12-cylinder crankcases. Designed to endure harsh operating envelopes—including cyclic discharge thermal stresses, heavy marine vibration profiles, and continuous duty condensing conditions—each unit features precision-machined gasket lands and discharge gas plenums to ensure uniform seal clamping and zero cross-chamber leakage.

Whether replacing cracked heads due to liquid slugging, high discharge temperatures, or fret damage from uneven bolt torquing, these assemblies restore factory volumetric efficiency and valve seating integrity.

Technical Details:

Key Features

1. High-Integrity Class 35B Cast Iron Construction: Exceptional damping against mechanical pulsations, superior heat dissipation under continuous heavy compression loads, and high resistance to thermal fatigue.
2. Precision CNC Ground Gasket Faces: Strict flatness within 0.03 mm to prevent discharge-to-suction blow-by, fretting, and head gasket failure under discharge pressures up to 31.0 bar (450 psig).
3. Direct Modular Inter-Bank Interchangeability: Standardized port geometry matching bank positions across 5H40 (2 heads), 5H60 (3 heads), 5H80 (4 heads), and 5H120 (6 heads / center-bank specific options).
4. Dual Cooling Configurations: Available in standard finned air-cooled profiles or water-jacketed variants for low-temperature R22/R404A/R507/R717 duty cycles.
5. Factory Hydrostatically Pressure Tested: Every casting is non-destructively inspected (NDT) and hydro-tested up to 1.5× maximum allowable working pressure (MAWP) prior to dispatch.

Compatibility & Cylinder Bank Configuration

• Carrier / Carlyle 5H40 & 5H46: 4-Cylinder models (Requires 2 Cylinder Heads).
• Carrier / Carlyle 5H60 & 5H66: 6-Cylinder models (Requires 3 Cylinder Heads).
• Carrier / Carlyle 5H80 & 5H86: 8-Cylinder models (Requires 4 Cylinder Heads).
• Carrier / Carlyle 5H120 & 5H126: 12-Cylinder models (Requires 6 Cylinder Heads, configured with outer banks and center-bank profiles).
• Compatible OEM & Licensee Units: Carrier Marine, Carlyle Refrigeration, Voltas 5H Series, and Ralco/DEC direct replacements.

Frequently Asked Questions

Are the cylinder heads interchangeable between Carrier 5H40, 5H60, 5H80, and 5H120 models?

Yes. The standard 2-cylinder head (MPN 5H41-1019 / 5H60-1004) is universally compatible across standard banks of the 5H40, 5H60, 5H80, and 5H120 compressors. However, for 12-cylinder models (5H120 / 5H126), the center vertical bank utilizes specific center-bank heads and cover assemblies (5H121-1019 / 5H120-1004) to clear manifold routing. Always verify your bank position before ordering.

Should I reuse the cylinder head bolts when installing a replacement head?

Reusing old bolts is not recommended. The 7/16″-14 head bolts undergo severe thermal cycling and elastic elongation. Reusing stretched bolts frequently results in inaccurate torque readings and subsequent head gasket leaks. Always install new Grade 8 capscrews and torque in accordance with service instructions.

Can a standard air-cooled cylinder head be converted to water-cooled?

No. Water-cooled heads feature a distinct casting equipped with internal cooling passages and a separate removable top cover sealed by gasket 5H41-1703. If your vessel or refrigeration plant operates in tropical marine climates with low suction temperatures or high pressure ratios, order the complete water-cooled head package (5H120-507 / 5H40-507).

What is the primary cause of cylinder head cracking in 5H compressors?

Hydraulic shock caused by liquid refrigerant or oil floodback into the compression chamber is the most frequent cause of structural casting fracture. Because liquids are incompressible, the excessive hydraulic pressure created as the piston reaches top dead center will blow the head gasket or crack the cast iron deck. Verify expansion valve superheat and crankcase heater function prior to recommissioning.