H
HACCP Hazard Analysis and Critical Control Point
HARP Hydrocarbons Additional Recovery Programme  (old, see also SHARP) 
HAT Higher Astronomical Tide
HAZ Heat Affected Zone
HAZAN Hazard Analyse
HAZID Hazard Identification
HAZMAT  Hazardous Materials 
HAZOP  Hazard and Operability Study
HAZWOPER  Hazardous Waste and Operations (USA) www.website 
HC  Hydro Carbon
HCA IHO Hydrographic Committee on Antarctica www.webpage
HCF Hydrochlorofluocarbon
HCM  Human Capital Management 
HCP  Hard Chrome Plated
HCR  Hydraulic Conductivity Ratio
HCV  Hand Control Valve
HDD Horizontal Directional drilling
HDLS  High Definition Laser Survey(ing) 
HDOP  Horizontal Dilution Of Precision
HDPE High Density PolyEthylene
HDR Historical Data Record
HEC Hyperbaric Evacuation Chamber
HEL Hyperbaric Evacuation Lifeboat
HELCOM  Baltic Marine Environment Protection (Helsinki) Commission 
HEMP  Hazards and Effects Management Process / Plan 
  Hourly Engine Maintenance Program 
  High Energy Magnetic Pulse 
  High-altitude Electro-Magnetic Pulse 
HES Hyperbaric Evacuation System
  Hazard Evaluation System 
HEX Heat Exchanger
HF Hydrocarbon Fire
High Frequency
HFC Hydrofluocarbon
HFD HVAC Flow Diagram
HFE  Human Factors Engineering 
HFIW High Frequency Induction Welding
HFL Hydraulic Flying Lead
HFO  Heavy Fuel Oil
HFP  HexaFluoroPropylene 
HFT Hook-up and Function Test
  Hydrogen Induced Cracking
HGE IMO-IHO Harmonizing Group ECDIS www.webpage  
HGMIO  IHO-IEC Harmonizing Group on Marine Information Objects www.webpage 
HGS Halliburton Geophysical Services (company) 
HHI Herfindahl-Hirschman Index (used in shares market)
HHV  Higher Heating Value (fuel characteristic)
HIP Hot Iso Static pressing
HIPAP High Precision Acoustic Positioning
HIPPS High Integrity Pressure Protection System
HIPS  High Integrity Protection System 
HIRA  Hazard Identification and Risk Assessment 
HISC  Hydrogen Induced Stress Cracking 
HLB Hyperbaric LifeBoat
HLO  Helicopter Landing Officer
HM Heavy Metal
HMEP Hazardous Materials Emergency Preparadness
HMI Human Machine Interface 
HMSO  Her Majesty's Stationery Office (UK) www.website
HND  Higher National Diploma 
HNS Protocol  Hazardous and Noxious Substances Protocol to OPRC Convention (OPRC website
HOCNF Harmonised Offshore Chemical Notification Format
HOO Head Of Operations
HP High Pressure 
  Hydrogen probe  
HPCC High Performance Computing Cluster;
HPHT  High Pressure-High Temperature (well)
HPLC High Performance Liquid Chromatography 
HPNS High Pressure Nervous Syndrome
HPU  Hydraulic Power Unit 
HPS Hydroacoustic Positioning System
HPWBM High-Performance Water-Based Mud
HPWJ High Pressure Water Jetting
HR High Resolution 
HRA   Hazard Risk Assessment 
  Human Reliability Analysis
HRC  High Resolution Camera
  High Resolution Converter 
  High Rupture Capacity  
  Hydrogen Release Compound
  Rockwell C Hardness (metallurgy)
HRT Hybrid Riser Tower
HS Hydraulic Supply 
  High Strength 
HSC  High Speed Craft 
  Hydraulic System Controler 
HSE Health, Safety, Environment 
  Health & Safety Executive 
HSEIA  Health, Safety & Environmental  Impact Assessment 
HSEMS  Health, Safety & Environmental  Management System  
HSEQ  Health, Safety, Environment and Quality
HSFO High-Sulfur Fuel Oil
HSL Health and Safety Laboratories
HSS  Heat Shrink Sleeve
HSV  High Speed Vessel
HSWA   Health and Safety at Work Act (UK Law) www.website 
HTC  Hydraulic Test Container 
HTI  Hand Tools Institute (USA) www.website
HTM  Hot Tap Machine  
HTMA Hydraulic Tool Manufacturers Association (USA) www.website
HTML  Hyper Text Mark-up Language 
HUC  Hook-Up and Commissioning 
HUET  Helicopter Underwater Escape Training 
HUMS  Health and Usage Monitoring System 
HV High Voltage ( = french HTA for High Tension A i.e. 1000<U<=50,000 AC or 1500<U<=75,000 DC) 
  ( = french HTB for High Tension B i.e. U>50,000 AC or U>75,000 DC)
HV Hand driven Valve
  Vickers Hardness see webpage
HVAC Heating, Ventilation and Air Conditioning 
HVOF High Velocity Oxygen Fuel (process)
HX  Heat Exchanger
HXT Horizontal X-Mas Tree
HYSON Hydrocarbon Services Nigeria Limited (a division of NNPC