HEES offers specialist mechanical and electrical services throughout the UK.

We have considerable experience in the installation of high purity pipework, clean utilities and specialist gases for the BioTech and Industrial sectors for applications such as pharmaceutical research, clinical trials and cGMP manufacturing.

On the electrical side, we have the resources and experience to renew, refurbish or modify a client’s electrical systems, as well as providing the electrical expertise in support of mechanical installation projects, such as process control systems.

Within the electrical side of the business, we also have a small team dedicated to the Automotive sector.

We carry out all project installations in accordance with the latest comprehensive Quality Assurance Systems and comply with all legislation, protocols and standards.


We design, install, commission and qualify:

  • Water for Injection (WFI) and Purified Water (PW) storage & distribution systems
  • Pure Steam
  • Demineralised water
  • Product process lines
  • Specialist medical gases

We use the latest enclosed head welding equipment from Orbimatic, the advantages of which are:

  • Consistent, repeatable, high quality fusion welding through PC control
  • Pipework from 1” to 6” with fully enclosed weld heads
  • Eliminate access problems with the latest compact welding heads, which are ideal for existing site support where space and convenience are restricted
  • Compliant with ASME BPE standards

Materials of construction – Carbon Steel, Stainless Steel, Alloys, Copper & ABS-uPVC.


Oue electrfical services include:

  • Design & installation
  • Electrical mains (HV & LV) & sub-mains (LV) power distribution
  • Lighting design & installation
  • Small power
  • Safety & security systems – fire, security, disabled alarm & access control
  • Data communications infrastructure & systems
  • Mechanical HVAC automation and control infrastructure & systems
  • Process automation and control infrastructure & systems
  • External lighting
  • TV & satellite installation
  • Audio visual infrastructure & systems
  • As-built drawings & client operating manuals
  • IEE regulations & NICEIC compliant testing & certification
  • Staff training

Quality Standards and Procedures

Large feeder tank outside plant - mechanical engineering

HEES carry out all project installations in accordance with the latest comprehensive Quality Assurance Systems.

We are accredited to ISO 9001, ISO 14001, OHSAS 45001.

Download copies of our:

Reference: International Organization for Standardization

We are also accredited with the British & European Compressed Gases Association and the NICEIC

Our weld technicians are all qualified to:

  • BS EN 287-1 welder approval.
  • BS EN 288-3 for TIG and MMA Weld procedures

All electrical installations are fully compliant with the Institute of Electrical Regulations BS7671:2018 (Amendment A1: 2020) and we are a National Inspection Council for Electrical Installation Contracting (NICEIC) registered contractor.

This provides clients with the comfort and security of knowing that all the electrical installations are backed up with a guaranteed standard by the NICEIC.

Our electrical control panels and distributed I/O are all constructed according to IEC & EN Standards, UL 508 & 544 NEMA and NEC or CSA.

Additional Resources from HEES

Mechanical engineering - reactor vessels

We recognise the challenges in maintaining site engineering & design resources so, in addition to our primary service offerings, we can also provide support and assistance to companies who are in need of additional resources.

We can provide:

  • Acad drawing facility
  • Utilities consultancy
  • Qualification and validation
  • Commissioning engineers
  • Installation management
  • ATEX installation and independent certification

Sub-assembly Fabrication

Industrial electrical control panel

We have listened to our customers and are now supplying modular sub assemblies.

Our standardised assemblies enable us to deliver, install and commission ahead of schedule and within budget.

Installation Management

A complete installation service is available to manage and support our customers applied resources.

Support & management covers:

  • Specifications and design to client performance brief
  • Engineering, design and drawing services
  • Budget and cost management
  • Mechanical services
  • Electrical services
  • Building services