Technical Toolbox
As a contractor, you are only as good as your last job. So being able to find information quickly and easily is an important skill. The following list of engineering resources in the form of charts, tables, graphs, definitions and links will hopefully make life easier. If you would like to see a particular topic added to the toolbox then let us know - select the link at the bottom of the page.
ASCII Character Table
The basic ASCII Character Table for numbers 0 to 127.
ATEX
EU directive 94/9/EC, compliance and equipment markings.
Cable Glands
The selection and sizing of cable glands.
CE Marking
CE Marks and their application.
COSHH
Control of Substances Hazardous to Health Regulations 2002.
Electric Motors
Formulas relating to electric motors
Electronic Wire and Cable
Stranding, diameters & areas of copper electronic wire & cable.
Glossary
Glossary of General Engineering Terms and Acronyms

Glossary of Nuclear Terms and Acronyms
Hazardous Areas
Classification of hazardous areas and comparison of standards
HAZIDs
HAZID studies and HAZID study guide words
HAZOPs
HAZOP studies and HAZOP study guide words
Hot Bolting
The practice of removing and replacing or freeing and re-tightening bolts on live piping and equipment
Hydraulics
Hydraulic Fluid Cleanliness - use of current standards

Comparison of ISO and NAS cleanliness classes
IncoTerms
Rough guide to the meaning of the 13 Incoterms.
Ingress Protection Ratings
IP Codes, and comparisons with NEMA system.
Machineability of Materials
Points to Note When Cutting.
Pipe Flanges
Pipe flange dimensions for common sizes and ratings.

Common terms for surface roughness of flange mating faces.
Pipe Schedules
Pipe schedules, wall thickness and weights.
Polarisation Index of Electric Windings
Use of Polarization Index for AC & DC drives and generators.
Power Factor Correction
Power Factor definition, calculation and correction techniques.
Pressure Gauges
Selection, installation & use of Bourdon tube pressure gauges.
Pump Affinity Laws
Affects of changing pump speed on flow rate, head and power.
Relief Valve Orifice Sizes
API standard Relief Valve Orifice Sizes
SI Units
The 7 base units and the derived units defined and explained.

Form decimal multiples and submultiples of SI units.
Safety Integrity Ratings
SIL Ratings and how to determine them.
Stainless Steels
Grades of stainless steels, their compositions and properties.
Straight Length Requirements
Straight Lengths needed & installation notes for Vortex Flow meters
Stud and Nut Sizes
Stud diameters & corresponding nut sizes in metric & imperial.
Temperature Classification
Temp class for hazardous area products - European & US
Thermocouple Types
Standard combinations of metals and their measuring ranges
Unit Conversions
On line conversion between all units of temperature.
Valve Leakage
Valve leakage classes and testing explained.
Vessels
Limits to the location of nozzles on vessels.
Viscosity
Definitions, units and conversions.