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Technical Parameters of PN16 and PN40 Valves
| Parameter | PN16 | PN40 |
|---|---|---|
| Nominal pressure | 16 bar at reference temperature | 40 bar at reference temperature |
| Typical body wall | Standard wall for general service | Thicker wall for higher pressure |
| Flange standard | EN 1092-1 Type 11 / 21 / 05 | EN 1092-1 Type 11 / 21 / 05 |
| Shell test pressure | About 24 bar | About 60 bar |
| Seat test pressure | About 17.6 bar | About 44 bar |
| Typical valve types | Ball, butterfly, gate, globe, check, strainer | Ball, gate, globe, check, strainer |
| Seat options | RPTFE, PTFE, EPDM, metal | RPTFE, PEEK, graphite, metal |
| Typical working temperature | -29 °C to +180 °C (soft seat) | -29 °C to +200 °C and higher with metal seat |
| Typical use | Water, air, steam, general process | Steam, high-pressure water, chemical and thermal oil |
Flange drilling examples (EN 1092-1)
| Size | Rating | Outside Diameter (mm) | Bolt Circle (mm) | Bolts |
|---|---|---|---|---|
| DN50 | PN16 | 165 | 125 | 4 x M16 |
| DN50 | PN40 | 165 | 125 | 4 x M16 |
| DN100 | PN16 | 220 | 180 | 8 x M16 |
| DN100 | PN40 | 235 | 190 | 8 x M20 |
Interchangeability is not automatic. At DN50, PN16 and PN40 flanges share the same bolt circle, but flange thickness differs. At DN100, outside diameter, bolt circle and bolt size all differ. A PN40 valve will often connect to PN16 flanges in small sizes, but it should not be assumed for all sizes, so we ask for the counter flange details when we quote.
Pressure falls with temperature. PN is a nominal rating at a reference temperature. At 200 °C a stainless PN16 valve may be limited to roughly two thirds of its rated pressure. We send a pressure-temperature chart with each quotation.
PN16 and PN40 Valve Range and Matching Components
Metric projects usually specify valves by DN size and PN rating, and require flanges, gaskets and bolting to match. We supply the complete joint set together with the valve, so engineers receive a coordinated package and installers have no missing parts.
| Product | Size Range | Rating Available |
|---|---|---|
| Flanged ball valves | DN15 to DN300 | PN16, PN40 |
| Flanged gate valves | DN15 to DN600 | PN16, PN25, PN40 |
| Flanged globe valves | DN15 to DN300 | PN16, PN25, PN40 |
| Flanged check valves | DN15 to DN600 | PN16, PN25, PN40 |
| Wafer and lug butterfly valves | DN40 to DN600 | PN10, PN16 |
| Double offset butterfly valves | DN50 to DN600 | PN16, PN25, PN40 |
| Flanged Y-strainers | DN15 to DN300 | PN16, PN40 |
| Flanges, studs, nuts and gaskets | DN15 to DN600 | PN6 to PN40 |
Choosing between PN16 and PN40
- PN16: suits most water, HVAC, general process and low-pressure steam systems.
- PN25: a common middle step for pump discharge and higher-temperature lines.
- PN40: suits steam, thermal oil, high-pressure water and demanding chemical duty.
- PN63 and PN100: available for special high-pressure projects on request.
Selecting one rating level above the strict need adds cost, while selecting one below creates risk. We encourage buyers to tell us the real maximum pressure and temperature, including surge and test conditions, so we can recommend the right level.
Buyer tip: give DN, PN, flange type and facing for every line in the inquiry, for example "DN80 PN16 flat face, Type 21". Clear data lets us choose the correct flange and face-to-face length at the first quotation, and avoids the delays that come from correcting simple mismatches at the order stage.
Standards Behind PN-Rated Valves
PN-rated valves belong to the European standards system, which has different rules from the American Class system. Using the correct set of standards makes sure the valve fits and is accepted by inspectors in countries that follow EN.
| Area | Standard Reference |
|---|---|
| Definition of PN | EN 1333 |
| Flanges | EN 1092-1 (steel), EN 1759 for Class flanges |
| Valve design | EN 12516 (shell design), EN 593 (butterfly), EN 12334 (check), EN 13709 (globe), EN 1984 (gate), ISO 17292 (ball) |
| Face-to-face dimensions | EN 558 |
| Pressure-temperature ratings | EN 1092-1 material groups, EN 12516-1 |
| Material | EN 10213 (castings), EN 10222-5 (forgings), EN 10088 (stainless) |
| Testing | EN 12266-1 and EN 12266-2, ISO 5208 |
| Pressure Equipment Directive | 2014/68/EU, for CE marking where applicable |
| Marking | EN 19 |
PN versus Class: PN is a metric rating tied to EN flanges, and Class is an American rating tied to ASME flanges. A PN16 flange will not bolt to a Class 150 flange, even where the pressure numbers look similar. A cross-reference table is useful, but it should not replace checking of flange dimensions on the actual project.
If your project documents mention a national standard such as DIN or GB, tell us and we will confirm equivalence with the EN or ISO standard we follow.
Reference note: EN standards are revised from time to time, and projects sometimes fix a specific edition in their specifications. Tell us which edition applies to your project, and we will confirm that our design and test procedures are consistent with it before production begins.
Certificates and CE Marking for PN-Rated Valves
For European buyers, a valve is not just a mechanical item, it is also a regulated product. The Pressure Equipment Directive applies to many valves above certain size and pressure limits, and the paperwork that goes with it can matter as much as the valve. We prepare documents with that in mind and explain which items apply to your order.
- EN 10204 3.1 material certificate: for body, bonnet, stem, ball or disc and bolting.
- CE marking and declaration of conformity: for qualifying models under the Pressure Equipment Directive, with the applicable module and category.
- Pressure test report: shell and seat tests per EN 12266-1.
- Dimensional report: flange drilling and face-to-face checked against EN 1092-1 and EN 558.
- Fire safe and fugitive emission reports: available for selected designs.
- Drinking water and food contact documents: for suitable seal materials, on request.
- Quality management: ISO 9001 style system and batch records.
- Third-party inspection: notified bodies, SGS, BV, TUV or the buyer's inspector can attend.
CE marking is not automatic. It depends on the model, size, fluid group and pressure, and only valves that have gone through the required conformity procedure can carry it. If your project needs CE-marked valves, tell us in advance, so we can confirm which products qualify and plan documentation and inspection.
We can send a sample declaration and documentation pack before order confirmation.
Audit tip: keep the EN 10204 3.1 certificate, the pressure test report and the declaration of conformity together for each delivery, referenced by valve serial number. Auditors and notified bodies usually ask for these three at once, and a complete set makes your file stronger during inspection.
Traceability and Marking to EN Requirements
For PN-rated valves, markings on the body are part of compliance as well as traceability. The marking identifies the manufacturer, the nominal size, the pressure rating and the material, and it allows an inspector to match the valve with its certificates in a few seconds.
- Body marking: DN size, PN rating, body material, heat number and manufacturer mark, following EN 19.
- Material records: mill certificates and PMI results are linked to the heat number of the body and key internal parts.
- Flange records: dimensional inspection of flange outside diameter, drilling and facing is filed with the valve serial number.
- Test records: pressure test results are recorded by serial number, with test date and operator.
- Nameplate: where required, a nameplate shows PN, size, temperature range, and CE or other marks.
- Document package: certificates and declarations refer to the same serial numbers shown on the valve.
| Marking | Meaning |
|---|---|
| DN | Nominal size of the valve in millimetres |
| PN | Nominal pressure rating of the valve |
| Material grade | For example CF8M or 1.4408 |
| Heat number | Link to mill certificate |
| Manufacturer mark | Identification of the producer |
| CE mark and notified body number | Where applicable under the directive |
Where a customer needs extra marking, such as a tag number, project number or purchase order, we can add it by laser marking or by a fixed nameplate.
Why markings matter: a clearly marked valve lets a maintenance engineer check size, rating and material without opening a file. In many plants, unmarked or poorly marked valves are rejected on arrival, so we apply markings that are permanent and readable even after painting or insulation work around the valve.
Testing Capability for PN-Rated Valves
Our testing procedures follow EN 12266-1, which defines test pressures, hold times and leakage rates for industrial valves. For valves marked PN16 and PN40, the test pressures are set from the rated pressure. We record the actual values and we can show them to inspectors.
| Test | Typical Value or Method | Frequency |
|---|---|---|
| Shell test, PN16 | About 24 bar (1.5 x PN), water | 100% of valves |
| Shell test, PN40 | About 60 bar (1.5 x PN), water | 100% of valves |
| Seat test, liquid | 1.1 x PN, with leakage rate to ISO 5208 / EN 12266-1 | 100% of valves |
| Low-pressure air seat test | About 6 bar air under water | 100% of soft-seated valves |
| Back seat test | Stem in open position, for gate and globe valves | 100% of valves |
| Flange dimension inspection | Drilling templates and calipers per EN 1092-1 | First article and sampling |
| PMI | XRF analyser | Incoming and sampling |
| Special tests | Fire safe, fugitive emission, cycle and cryogenic | Type test reports on request |
Understanding leakage rates: EN 12266-1 defines leakage rates from A (no visible leakage) to G (largest). Resilient-seated valves normally meet rate A, and metal-seated valves often meet rate C or D, depending on design. Please specify the required leakage rate in your inquiry, because it affects the seat selection and the cost.
You may attend the tests or ask for a video of the pressure gauge and hold time for your own records.
Reading the test report: a good test report lists the test pressure, the medium, the hold time and the result for each valve serial number. If your specification asks for a different hold time or a higher test pressure, mention it in the inquiry, and we will adapt the test procedure and report format.
Frequently Asked Questions about PN16 and PN40 Valves
Q: What does PN16 mean?
PN16 means nominal pressure 16 bar. It is a reference designation, and the actual allowable pressure depends on the material and the temperature, which normally reduces as the temperature rises.
Q: Can I use a PN40 valve in a PN16 system?
Mechanically a PN40 valve can often work in a PN16 system, but the flanges may not match. Check outside diameter, bolt circle, bolt size and the number of bolts, which can differ.
Q: Can I use a PN16 valve in a PN40 system?
No. The valve rating would be below the system rating, which is unsafe. Always select a valve with a rating equal to or higher than the system.
Q: How do PN and Class ratings compare?
Class 150 is roughly equal to PN20 and Class 300 to PN50 in terms of pressure at room temperature, but the flanges are not interchangeable. Use cross-reference only for pressure comparison.
Q: Is PN25 a standard rating?
Yes. PN25 is a common intermediate rating in EN 1092-1, but not all valve types are made in PN25. We can quote it on request.
Q: Does the pressure rating change with temperature?
Yes. Stainless steel loses strength as temperature rises, so the allowable pressure at 200 °C is lower than at ambient. We supply a pressure-temperature chart.
Q: What test pressure do you use?
We use 1.5 times PN for the shell test and 1.1 times PN for the seat test, in line with EN 12266-1, unless your specification requires otherwise.
MOQ and Pricing for PN16 and PN40 Valves
Our minimum quantities are designed for project buyers and distributors. Mixed ratings and sizes can be combined in one order, which helps you reach the minimum without over-buying.
| Item | Typical Terms |
|---|---|
| Sample order | 1 to 3 pieces per model |
| Standard MOQ | 20 to 50 pieces per size; mixed PN16 and PN40 accepted for the same model |
| Large sizes | Single pieces accepted for projects and replacements |
| Pricing basis | EXW, FOB Ningbo, CFR or CIF in USD |
| Quote validity | 30 days, adjusted for stainless steel and nickel price changes |
| Payment | 30% T/T deposit, 70% before shipment; L/C at sight for approved accounts |
PN16 versus PN40 price guide
As a rough guide, a PN40 valve costs about 25 to 60% more than the PN16 equivalent, depending on type and size, because of thicker walls, larger flange thickness and sometimes heavier internals. Ball valves show a smaller difference, and gate and globe valves a larger one.
- Right-sizing the rating: use PN16 where the real pressure allows, and PN40 only for the lines that need it.
- Cast or forged: forged bodies for PN40 small sizes cost more than cast.
- Documents: CE marking and third-party inspection add cost.
- Material: 316L and duplex raise the price.
Send us the line list with pressure and temperature, and we will propose the economical rating for each line.
Ordering advice: combine PN16 and PN40 items in the same enquiry. The combined quantity improves pricing and lets us arrange common production and shipping, and your team receives one coordinated package rather than two separate deliveries with different dates and documents.
Lead Time, Customisation, Packaging and Trade Terms
Lead time and stock
Standard PN16 flanged ball valves and check valves in popular sizes ship in 20 to 30 days. PN40 valves, large sizes and orders with CE marking or special tests need 35 to 55 days. We give a production schedule at order confirmation.
Customisation
We can customise flange drilling, face-to-face length, facing type, material grade, seat material, stem extension, operator and marking. For replacement orders, we can match the dimensions of an existing valve and propose improvements.
Packaging
- Flange faces protected by plastic or wooden covers
- Individual cartons for small valves, wooden cases or pallets for heavy ones
- Ball valves shipped with the ball in the open or half-open position
- Labels with DN, PN, material, heat number and project reference
- Neutral or customer-branded packaging on request
Shipping and trade terms
| Term | Details |
|---|---|
| Incoterms | EXW, FOB Ningbo, CFR, CIF, DAP |
| Port | Ningbo-Zhoushan; Shanghai as an alternative |
| Transport | Sea freight, air freight for urgent items, express courier for samples |
| Documents | Invoice, packing list, bill of lading, origin certificate, material and test certificates |
We can ship PN-rated valves together with flanges, gaskets and bolts in one consolidated order, which helps reduce freight and handling costs.
Handling advice: keep flange covers on until installation, lift valves with slings around the body, not around the actuator, and store them in a dry place. Following these steps protects sealing faces and surface finish, which are the parts that most often suffer between delivery and installation.
