Solutions · Design and material

What information piping design needs

A pipeline is not ordered by nominal size but by what it is supposed to do. This page names the ten items every design has to clarify – from building installations to large-scale plant construction – and says for each what the designer derives from it for the parts list. Design is done by the plant designer, specialist planner or installer – we supply the material. What we need is the part specification of every item – clear, complete, fully specified.

For whom: Specialist planners, installers, plant builders, purchasing – and everyone preparing an inquiry
What we do: Supply material according to your parts list, with certificates per item; the design remains with the designer
What the designer clarifies: Medium · pressure and temperature · flow rate and nominal size · regulations · material and certificate · connection · insulation · expansion and supports · testing · documentation
What we need: Per item: standard and type · material · size · version · certificate type · quantity – plus the regulations the order is placed under

The ten items – and what the designer specifies for us from them

The order is that of the design: from the medium follow pressure and temperature, from these material and wall thickness, from these connection, supports and testing. The designer needs the ten items to know which parts to use. We need the result: the part specification of every item. How the designer gets from the information to the parts list is his business – the right-hand column only says what finally goes to us.

Core items of a piping design (reading aid, not an extract from regulations)
#	Item	What the designer defines	What of it goes to us in the parts list
1	Medium	Which substance flows, in which state (liquid, gaseous, two-phase), how pure, how corrosive, whether drinking water, food, gas or hazardous substance. The medium decides material, gasket and regulations.	Nothing directly – from the medium the designer derives material and sealing material and specifies them to us per item. The medium itself may appear as a header line but does not replace any item.
2	Pressure and temperature	Design pressure and temperature (what the calculation is based on) and operating values. From these follow the pressure rating (PN or Class), the wall thickness and the question whether the Pressure Equipment Directive applies.	The pressure rating chosen for each flange (PN or Class) and the wall thickness for each pipe and fitting – as information in the item: Pipe flanges.
3	Flow rate and nominal size	From the flow rate and the permissible flow velocity follows the inside diameter, from the pressure loss along the length the final nominal size. This is design work – we take over the nominal size, not the calculation.	Nominal size DN or outside diameter × wall thickness per item; for system pipes the dimension of the system (e.g. 28 × 1.2).
4	Regulations	Which rules apply: Pressure Equipment Directive and category, drinking water regulations and installation rules, gas, steam, refrigeration, fire protection; piping standard (European standard for metallic industrial piping, AD 2000 code, ASME B31). The regulations define which certificates and tests are required.	The designer states under which regulations the order is placed – as a header line of the parts list (“AD 2000”, “drinking water installation”) and as certificate type per item.
5	Material and certificate type	Material per line according to medium, temperature and regulations; plus the document to EN 10204 (test report 2.2, inspection certificate 3.1 or 3.2) and whether traceability per item is required.	Material number or name (1.4404, P235GH) and certificate type per item – the most important line of the specification; a 3.1 can hardly be obtained afterwards: Inspection documents to EN 10204 · Materials.
6	Connection type and facing	Welding, flange, thread, pressing, groove or clamping – one per section. For flanges type, pressure rating and facing (raised face, tongue and groove), plus gasket and bolts.	The type per item: for flanges type, pressure rating and facing, for press systems the system and dimension, for threads the thread type: Pipe flanges · Press systems · Joining without welding.
7	Insulation	Thermal, cold or sound insulation and its thickness; vapour barrier for cold. The insulation thickness determines centre distances, clamps and wall penetrations.	The parts chosen from it as items – clamps with insulating insert, pipe sections, pre-insulated pipe.
8	Expansion and supports	Change in length from temperature difference and material, fixed points and sliding points, expansion compensation by legs, bends or expansion joints, permissible support spans per nominal size and filling.	Clamps, sliding and fixed-point supports, expansion joints and U-bolts as specified items with quantities from the designer’s support plan: Pipe supports · Pipe clamps.
9	Testing and acceptance	Pressure or leak test (test medium, test pressure, duration), flushing and disinfection for drinking water, non-destructive testing of welds, acceptance by a notified body or the operator.	The certificate type per item (3.2 instead of 3.1 if an inspection body is involved) and test plugs, blind flanges or test bends as separate items: Inspections.
10	Documentation and piping class	Piping class (which parts with which material, wall thickness and certificate belong to which medium), isometrics, parts list, marking, documentation for operator and authority.	The parts list itself – item, quantity, line number on request. The piping class is the designer’s tool from which he derives the parts list: Certificates and documentation · Packaging and marking.

Structure and content in our own words after the textbook Franke/Platzer “Rohrleitungen – Grundlagen, Planung, Montage” (chapter 3 dimensioning, 4 routing, 5 installation) and the Tabellenbuch für den Rohrleitungsbau; no standard texts, no calculation formulas. The right-hand column is our statement as supplier.

What we do

Design is done by the plant designer, specialist planner or installer – we supply the material. Pipe network, wall thickness and expansion are defined by the designer – we take over their specification. What we do: compile the items from your parts list, check material, standard and certificate type per item, supply flange, gasket and bolts as a set on request, allocate certificates per item and pick by line on request. For this we do not need the ten items but the part specification of every item. If something is missing there, we ask before we order – that is faster than a return.

Building services in depth: what a pipe network designer asks

In drinking water and heating installations, design usually lies with the specialist planner or the design service of a system manufacturer. In general the pipe network designer needs the following information; answering it in advance shortens the design by days. The structure follows the rules for drinking water installations (DIN 1988-300, EN 806-3) – only what is asked is given here, not the calculation.

Drawings as DWG or DXF with locations of house connection, manifolds, risers, draw-off points and flushing stations.
Minimum pressure after the water meter and supply pressure, distance to the house connection.
Circulation yes or no; hot water central or decentralised (fresh water or apartment stations with data sheet).
Installation type: loop-through ring, series or tee – it determines pipe quantities and dimensions.
Insulation on site or pre-insulated; fire protection penetrations.
Special valves and outdoor taps with position and data sheet.
Heating: adjusted heat load per radiator (a specific value per square metre is not enough), flow temperature and temperature difference, radiator type and connection or valve variant, heat meters.
System: which press or push-fit system, which pipe material (stainless steel, copper, multilayer, carbon steel for closed circuits) – and whether mixed installation occurs.

For the order with us, the designer’s parts list follows from this: system and dimension per item, pipe lengths in bars or coils, fittings with article number or unambiguous designation, insulation and fixing as separate items. Transitions between systems and materials are separate parts: System finder · Mixed installation and corrosion · System transition.

Question list after the project checklists of system manufacturers (manufacturers’ documents, class H – taken over as a question list, supplier-neutral) and the design notes of system manufacturers; structure after DIN 1988-300 and EN 806-3 only named, not reproduced.

Plant construction in depth: from the piping class to the parts list

In plant construction, design starts with the piping class: per medium and pressure rating it defines the material of pipe, elbow, tee, reducer, flange, gasket and bolt, the wall thickness per nominal size, the flange type and facing, the certificate type and the tests. The isometric per line then only counts pieces and length. Piping class and isometric together give the parts list – and the parts list is what we need.

What a piping class defines and what of it goes to us in the parts list (invented example lines, carbon steel)
Definition in the piping class	Example	What goes to us in the parts list
Material and product standard	Pipe P235GH to EN 10216-2, fittings to EN 10253-2, flanges P250GH to EN 1092-1	Standard, material and type per item exactly like this; dual certificates as the mill certifies them – the certificate checklist shows what to check in the certificate
Wall thickness per nominal size	DN 50: 60.3 × 2.9; DN 100: 114.3 × 3.6	Pipe and fittings per item with the wall thickness of the piping class, so that the welding ends match
Flange type, pressure rating, facing	Weld neck flange type 11 PN 40, raised face form B1	Flange, gasket and bolts as separate items – as a set per joint on request: Pipe flanges · Gaskets
Certificate type	3.1 to EN 10204 for all pressure-bearing parts, 2.2 for bolts	Certificate type per item in the parts list; 3.2 only when ordered with an inspection body
Tests and marking	Heat number on every part, colour marking per material	Colour marking and labels per line only if agreed in advance: Packaging and marking

The added value lies in the allocation: whoever orders project supply and agrees this with us in advance gets the delivery picked by line, the certificates sorted by item and the delivery notes with line number – the basis of the project documentation: Project supply · Certificates and documentation.

Terms piping class, isometric, parts list after the textbook Franke/Platzer (chapter 5 installation, prerequisites and prefabrication) and the practice of the project business; the example lines are invented, not a specification. The statements on our services are ours.

Checklist to send with your inquiry

For a material inquiry we need the part specification per item – as a parts list in the e-mail, as a table or as an export from your design:

Standard and type (e.g. weld neck flange EN 1092-1 type 11, elbow EN 10253-2 type A 90°)
Material (material number or name) · certificate type to EN 10204
Size: nominal size or outside diameter × wall thickness, pressure rating PN or Class, facing for flanges
Version (black, galvanized, pickled, sealing material for systems) · quantity and length
As header: regulations the order is placed under · delivery date and delivery address · line number per item on request

What is missing, we ask for. What we do not supply, we say – and name who can.

Frequently asked questions

What information does piping design need?

Ten: medium, pressure and temperature, flow rate and nominal size, codes, material and type of certificate, type of joint, insulation, expansion and supports, testing, documentation.

Can you design the pipeline for us?

No – design is done by the specialist planner or installer. We check your parts list for material, standard and certificate type and supply the material.

We only have the nominal size – is that enough?

Not for a quotation: we need standard, type, material, size, version, certificate type and quantity per item. Medium, pressure and temperature help the designer with the selection – what helps us is the finished specification.

What is a piping class?

A definition per medium and pressure rating of which parts are to be installed in which material, with which wall thickness, flange, gasket and certificate. Plant builders keep it as a table.

Do we always need a 3.1?

No – the regulations decide. Pressure-bearing parts under the Pressure Equipment Directive usually yes, building installations usually no (system approval and marking). A 3.1 must be requested with the order.

Parts list ready? Then let’s go.

Send us your parts list – each item clearly specified – and we reply with items, certificate type and delivery time.

Send an inquiry

Your inquiry to Zickwolff

Send us what you have – designation, standard, quantity, date. We will clarify the rest with you.

One item or a question

Send inquiry

Not in stock? We procure it – single items too.

Designation, standard and quantity are enough.

Several items

Send bill of materials

200 items? One parts list is enough – we deliver complete.

Attach it as a file.

Helpful if already known: project and country, date needed, certificates, packaging and language of the packing lists. If anything is missing, we will ask.

It is urgent

Request express

When do you need it? Express delivery, to the site if required.

Tell us by when you need the material – we will tell you what is possible.

← Back to the solutions

As of 2026-10-24. Technical content in our own words after textbook (Franke/Platzer, Rohrleitungen) and Tabellenbuch für den Rohrleitungsbau; building services question list after manufacturers’ documents, supplier-neutral; DIN 1988-300 and EN 806-3 named as structure only. No design service, no legal advice.