Dickinson Hotwork Services (Pty) Ltd provides a complete range of On-Site Heat Treatment Services to the metals smelting, mineral processing, chemical, refining and thermal power industries. These Hotwork Services are tailored to maximise the life of clients’ operational assets; they will be described in more detail below.
PRE / CONCURRENT HEAT
Dickinson Hotwork Services (Pty) Ltd’s Pre / Concurrent Heat systems minimise the heat difference between welding areas and their surrounding work pieces during welding operations. The techniques reduce moisture and thermal strains, thereby preventing cracking during welding and prolonging the life of welds. Typical applications include pipe work and repairs to pressure vessels or high strain areas.
POST WELD HEAT TREATMENT (PWHT)
The company’s PWHT processes involve the heating, soaking and cooling of metals at calculated rates to return the molecular compound to their initial state; after welding operations. This eliminates stresses caused by welding, avoiding cracking or complete failure of welds. The PWHT parameters vary according to the material, material thickness and welding techniques. PWHT is most commonly used on pressure vessels, high pressure pipe work and high strain areas.
EXPANSION FITTING OR REMOVAL
Our Expansion Fitting or Removal techniques involve the accurate and even heating of gears, bearings or bushes for expansion, allowing them to be fitted or removed as required.
In the De-Gassing process, heat is applied to expand the molecules of a metal releasing hydrogen gasses, allowing the material to be welded and re-used.
ANNEALING, HARDENING OR NORMALIZING
Heating and cooling metals at calculated rates in order to harden, soften or normalise them. This is commonly done on castings, materials needing machining and cold formed metals.