Cost comparison calculator: what does the joint cost – pressed, welded, grooved or flanged?

Economy calculator: time, cost, downtime

Worked example: two scenarios, time only

Calculated with this calculator’s defaults and fictitious inputs. Without material and without prices: press fittings cost more than weld fittings – that belongs in your own calculation.

• A: new build, heating distribution DN 50 in a hall – DN 32-50, 6 elbows, 2 tees, 1 couplings (= 20 joints), Working conditions: normal – building site.
• B: maintenance, cooling water line DN 50 during running production – DN 32-50, 3 elbows, 2 tees (= 12 joints), Working conditions: difficult – existing plant, confined, at height.

Plant downtime = assembly time, for hot work (welding, flange) plus 1 h of follow-up inspection (assumption for this example). Grooved couplings are not in the example: in practice they are used from DN 65.

How to calculate

• Time comparison: size and the fittings are enough – the calculator counts the joints from them (elbow 2, tee 3, socket 2) and shows the assembly time per method. Count reducers and reducing tees as a socket or tee of the larger size; with the calculator's broad size classes a reducer usually stays in the same class. The working conditions scale all methods evenly: good for workshop and free access, normal for the site, difficult for work in existing buildings, in confined spaces or at height.
• Cost comparison: with your hourly rate the costs are added. Under “Calculate in more detail” you enter fitters, material cost per fitting, set-up time, testing and – only for hot work – fire watch and permit. As soon as fixed costs or material are entered, the calculator states from how many fittings a method pays off against the chosen reference.
• Downtime: for industry and maintenance, enter the downtime cost per hour. With production running, assembly time is often the smallest item – what decides is how long the line has to be empty and cold.

Where the presets come from – and why you should change them

The assembly times per method and size class are presets – rough guide values and experience values, not measurements from your site. They apply to one joint under good conditions, including cutting to length and setting up, and they stand on the same basis for press, grooved, thread and welding, so that no method is favoured by the choice of figures. How far your site deviates from that – access, installation position, weather, wall thickness – you set with the working conditions; they apply equally to all methods. For orientation, a range for site conditions is shown beside the values. The flange is calculated as bolting; the welding-on of the two flanges is added by the calculator as two weld seams. For sizes from DN 125 there is no preset – there the calculator works with your times. Manufacturer claims such as “up to 60 % less time than welding” (Viega Megapress, up to 80 % in XL) we quote as such on the system pages; they do not enter the calculation as a figure. Every time can be overwritten. Whoever has their own experience values – from the last project, from the post-calculation – enters them and gets a result that fits their business. Size, position, access, material and wall thickness change the times considerably; the calculator reflects that through the size class and your set-up time, not through a formula that knows everything.

What the calculator cannot do

It does not check whether a method is permissible for your application at all – that is what the system finder does for medium, pipe and size and the comparison matrix for the technical criteria. It knows no tariffs, no surcharges, no regions and no prices; material costs are your input. It calculates with averages per size class, not with your specific installation position. And it replaces neither the contractor's costing, nor the design, nor the manufacturer's approval. What it can do: put the quantities that are usually only felt in the “press or weld” discussion into an order – traceably, with visible assumptions, for your figures.