From a seriesto a one-offproject

Why a production flow and one-off units coexist in the same shops

Series work and one-off work only conflict where a factory has been built around a single type of work. If all the tooling is set up for one particular size, any departure from it breaks the schedule. If a company lives from project to project, it never accumulates a technological base, and every routine supply costs more than it should.

We separate these modes by manufacturing route rather than by shop. Incoming inspection of steel, the welding stations, weld inspection, assembly and the test rigs are shared by every product: a catalogue boiler and a heat-recovery boiler built to customer drawings go through exactly the same checks. What differs is the volume of design work before metal is cut and the number of approvals on your side, and that is what sets the lead time and the price.

When a catalogue model pays off and when a bespoke project does

Choosing how the order is handled is a balance between the cost per kilowatt, the lead time and how precisely the equipment fits your process. The closer your task is to a standard one, the less you pay for engineering work. The further your process is from the mainstream, the more expensive it becomes to force it into a catalogue solution: excess fuel consumption and reworked pipework on site swallow the saving made on the first invoice.

Series production

Standard catalogue models, 60–90 days. The lowest cost per kilowatt. Suitable when the heat-carrier parameters, the fuel and the boiler house layout all fall within the standard range.

Adapted standard model

A standard model reworked for particular dimensions, non-standard fuel or a specific climatic version, 75–120 days. The base design stays proven; only the components the site demands are changed.

Bespoke project

A boiler for special requirements: unusual heat-carrier parameters, particular steel grades, integration into an existing line. Lead time 90–180 days, a substantial part of which is calculation and approvals.

Made to customer drawings

Manufacture to your own design documentation, 120–240 days. Design supervision is included: the documentation is reviewed before production starts.

Modernisation

Overhaul and upgrading of boilers from any manufacturer, including replacement of the heat exchanger and the shell. The lead time follows from the scope of work established by the survey.

Spare parts

Manufacture of spare parts to drawings for Boilte boilers and those of other makers, 30–90 days. For cases where the supplier is no longer available or the delivery time for a genuine part is unacceptable.

The boundaries between these models are movable. A conversation often starts with a bespoke project, and once the input data has been examined it turns out that an adapted standard model closes the task: the customer gets the same result two months earlier. The reverse happens too — a catalogue boiler matches the required output, but the way the plant runs makes it uneconomical.

What actually changes when a standard model is adapted

Adaptation is not a cosmetic edit. We recalculate the thermal scheme and confirm that the modified design keeps its design efficiency and service life. Most often the work touches four groups of parameters.

Dimensions and layout

Position of the nozzles, the service side, the height of the flue. A typical task when replacing equipment in an older boiler house where the door opening and the foundation cannot be touched.

Fuel

Switching to a fuel the model was not designed for changes the furnace volume, the arrangement of the heating surfaces and the requirements for the burner.

Climatic version

Cold-climate sites and outdoor installation call for different steel grades, different insulation thicknesses and frost protection for the pipework.

Load profile

A boiler that spends most of the year at half load differs in design from one running at constant load: the turndown range is built in at the adaptation stage.

The earlier you tell us about constraints of this kind, the less they cost. A change on the drawing costs engineering time; the same change after cutting costs steel and a place in the schedule.

How we work to a customer's design documentation

Large plants and design institutes often come to us with a complete set of drawings, either their own development or documentation for a product that is no longer made. We accept such orders and treat the documentation as an obligation: departures from it are possible only by written agreement.

Before metal is cut, the design office reviews the documentation: completeness, whether the specified materials match the available stock range, the manufacturability of the welded joints, and whether the seams can be inspected in the positions shown. If a joint cannot be properly welded and inspected in the layout as drawn, you hear about it before manufacture begins rather than at the acceptance. Comments are issued in writing and the decision on each one remains yours. The lead time of 120–240 days is explained by this stage and the process planning that follows.

Modernisation and spare parts instead of buying a new boiler

Replacing a boiler outright is not always justified. If the shell and the refractory lining are in acceptable condition and only certain components have reached the end of their life, an upgrade costs less and fits into a short shutdown window, which for a plant in operation often matters more than the price. We work with equipment from any manufacturer, including models that are out of production.

Any discussion of an upgrade starts with a survey: without an assessment of the actual condition of the steel and the welds, an estimate would be notional. Spare parts are a separate matter: manufacture to drawings within 30–90 days. If there is no drawing, we work from a sample and recover the dimensions and the material from the actual part.

What determines the lead time and how not to stretch it

The ranges quoted are manufacturing times on the assumption that input data and approvals arrive on time. Experience shows that a missed schedule almost never originates in production: delays accumulate at the interface between customer and factory.

Complete input data

Heat-carrier parameters, fuel characteristics, control system requirements, installation conditions. An incomplete questionnaire is a common reason for a project stalling.

Speed of approvals

Every round of comments adds weeks if several departments have to sign off. One accountable representative speeds a project up more than any measure taken at the factory.

Changes after release to production

Amending the design at the cutting or assembly stage means sending the product back to a previous operation. We state the cost before starting.

Bought-in components

Burners, valves and controls have delivery times of their own. We quote them separately from the manufacturing time for the boiler.

Testing and acceptance

Hydrostatic testing and rig running are included in the lead time. The date of a witnessed acceptance is worth fixing well in advance.

We do not shorten a lead time by cutting the scope of inspection: a product that has not been through the full cycle of checks creates problems during commissioning and in its first season.

Where an order begins

Start with the task, not with the model. Tell us which process needs heat, what heat-carrier parameters are required, what fuel is available and in what conditions the equipment will stand. That is enough for us to propose one or two routes at different prices and lead times and to explain how they differ in service. If the choice is difficult, start with a visit to the factory: seeing the shops and discussing the solution with our engineers is a normal stage of project approval before a purchase.