Nitrogen valve

Nitrogen valve: technology, application and the right choice

Nitrogen valve: the working principle in practice

A nitrogen valve is used across industry for blanketing, purging, pressurising and for handling nitrogen as an inert transport gas. The subject of nitrogen valve touches both the construction of the valve and the way the plant is operated. It pays to understand the working principle behind nitrogen valve first, because the limits follow from that principle. In hot oil and thermal oil service packing creep and coking on leakage are the issues, which calls for a packing system that retains preload. Hydrogen has a very small molecule, so a seal that is adequate for nitrogen may still leak on hydrogen. Hydraulic systems work with high pressure and small volumes, so leakage quickly leads to pressure loss and contamination. That principle explains why nitrogen valve behaves differently from a standard execution under heavier duty. With nitrogen valve it pays to include phase changes in the medium, because those sharply increase the load on the seal. For nitrogen valve this means that construction and operating conditions cannot be judged separately. Oxygen is not flammable in itself but accelerates any combustion, which is why an oxygen valve must be degreased and assembled clean. Vacuum service reverses the requirement, because atmosphere pushes inwards and the seal has to hold from outside to inside. In practice nitrogen valve is rarely a standard question once medium and temperature move away from average.
Schroeder Fluid loop test system

Executions and materials for nitrogen valve

Nitrogen itself is chemically inert, so the demands come from pressure, cleanliness and leakage rather than from corrosion. How nitrogen valve behaves under varying load says more about the quality of the selection than behaviour under steady load. In practice we find that most failures around nitrogen valve come not from the material but from a wrong assumption during selection. In liquid form nitrogen sits at minus one hundred and ninety six degrees, which turns the same duty into a cryogenic problem. Hydrogen also brings embrittlement into play, which rules out certain steel grades and hardness levels. Cryogenic service starts roughly below minus one hundred degrees, and there the properties of almost every material change. The medium governs a valve more than any other factor, because it fixes material selection, sealing and safety requirements. Because nitrogen displaces oxygen, leakage into a confined space is a safety issue and tightness is specified accordingly. Cryogenic valves belong on a low temperature test, because a test at ambient says little about behaviour at minus one hundred and sixty degrees. On a new medium we always advise a compatibility check up front rather than an assumption based on a comparable plant. On nitrogen valve we always check the full operating envelope, including start up and shutdown. A correct execution of nitrogen valve accounts for real operating conditions and not only for design values.

Sectors and applications for nitrogen valve

Applications run from air separation and gas distribution to blanketing in chemical plants and purging during maintenance. Chemicals and petrochemicals bring the widest variety of media and therefore the most bespoke questions. In pharmaceutical and food production the drivers are cleanliness, flushability and demonstrable material traceability. Our customers use nitrogen valve in positions where a failure has immediate consequences for production. In an existing plant nitrogen valve is often part of a wider question about availability and maintenance. On project supply we record per position which execution of nitrogen valve was delivered, including materials and tests. In plants where nitrogen valve is applied, the emphasis is on reliability rather than lowest purchase price. In technical gases the subject is oxygen, nitrogen, argon, hydrogen and mixtures, each with its own cleanliness and safety requirements. Alongside QUADAX and PRUSS we represent Pibiviesse, Schroeder, Striko, Malbranque, Daume, FluoroSeal and Guichon, so we can select the right brand for each project. Dutch Valve Vision operates under a KIWA ISO 9001 certified quality system, which in the RFQ stage of chemical and offshore projects is usually a hard requirement. Demand for nitrogen valve reaches us mainly from projects where the standard range falls short. On replacement we always check the existing installation dimensions for nitrogen valve, so the pipework can stay untouched.
STRIKO Valves

Specifying nitrogen valve correctly

Where nitrogen valve forms part of a safety function we record the fail position and required stroking time explicitly. For hazardous media we look at the required leakage class and at the emission requirements that follow from the permit. Phase matters too, because a medium that flashes inside the valve behaves completely differently from one that stays liquid. Degreased execution, nitrogen purging and sealed bagging are not extras on oxygen and high purity duty but part of the delivery. On nitrogen valve we also state what an execution cannot do, because that prevents more problems than a list of advantages. The required leakage class often drives the choice around nitrogen valve more strongly than the budget does. For nitrogen valve total cost of ownership weighs more than purchase price, certainly when replacement has to happen during a shutdown. A wrongly chosen seal on an aggressive medium is almost always the cause of premature leakage, not the body. Cleaning procedures for oxygen service are recorded in the documentation, including the agents used and the packing method. For an accurate quotation we need the nominal diameter, the pressure class, the medium, the operating temperature and the required actuation. Standardising across several positions makes nitrogen valve simpler in maintenance and in spare parts management. The cleaning and flushing procedure counts too on nitrogen valve, because it can be more aggressive than the process itself.
TOSV butterfly valve

Ordering nitrogen valve from Dutch Valve Vision

We think along on the spare parts strategy for nitrogen valve, so critical positions stay covered. We think along from the basic specification through to the tag plate, and supply documentation that a buyer or inspector accepts without discussion. For nitrogen valve you can come to Dutch Valve Vision for the selection, the delivery and the support afterwards. We supply nitrogen valve as a loose product or as a fully assembled unit with actuator and accessories. We quote a realistic lead time rather than an optimistic one, because a missed delivery date costs more than an extra week in the planning. On repeat orders we record the configuration, so a follow up delivery is identical to the first and installation holds no surprises. We keep the configuration data for nitrogen valve on file, which saves a great deal of searching if a fault occurs later. On nitrogen valve we make sure the chosen execution demonstrably meets the stated standards rather than merely looking plausible on paper. We record which execution of nitrogen valve was delivered, so a follow up delivery or spare part matches exactly later on. Our specialists are happy to discuss nitrogen valve on the basis of your P&ID, your datasheet or simply a photograph of the situation. Dutch Valve Vision stays available after delivery of nitrogen valve for technical questions and for parts. Send us your DN, pressure class, medium and temperature at sales@dutchvalvevision.com, or call +31 (0)70-2210560 to speak to a specialist.
Striko mengers en breekplaten

Frequently asked questions about nitrogen valve

What exactly does nitrogen valve mean?
Oxygen is not flammable in itself but accelerates any combustion, which is why an oxygen valve must be degreased and assembled clean. The medium governs a valve more than any other factor, because it fixes material selection, sealing and safety requirements. Hydraulic systems work with high pressure and small volumes, so leakage quickly leads to pressure loss and contamination. Hydrogen has a very small molecule, so a seal that is adequate for nitrogen may still leak on hydrogen. In most projects nitrogen valve turns out to be less standard than it first appears. We see this come back regularly in enquiries about nitrogen valve, and the answer is rarely a single sentence. Anyone looking into nitrogen valve quickly runs into a choice that goes beyond picking a catalogue number. Dutch Valve Vision operates under a KIWA ISO 9001 certified quality system, which in the RFQ stage of chemical and offshore projects is usually a hard requirement.
Nitrogen itself is chemically inert, so the demands come from pressure, cleanliness and leakage rather than from corrosion. In liquid form nitrogen sits at minus one hundred and ninety six degrees, which turns the same duty into a cryogenic problem. Cryogenic valves belong on a low temperature test, because a test at ambient says little about behaviour at minus one hundred and sixty degrees. Cleaning procedures for oxygen service are recorded in the documentation, including the agents used and the packing method. For nitrogen valve a good specification up front is cheaper than a correction afterwards. That makes nitrogen valve a subject where discussion up front pays for itself in operation. What weighs heaviest on nitrogen valve in practice is the combination of temperature and differential pressure, not either one alone. Alongside QUADAX and PRUSS we represent Pibiviesse, Schroeder, Striko, Malbranque, Daume, FluoroSeal and Guichon, so we can select the right brand for each project.
Hydrogen also brings embrittlement into play, which rules out certain steel grades and hardness levels. Because nitrogen displaces oxygen, leakage into a confined space is a safety issue and tightness is specified accordingly. On a new medium we always advise a compatibility check up front rather than an assumption based on a comparable plant. In hot oil and thermal oil service packing creep and coking on leakage are the issues, which calls for a packing system that retains preload. We always explain why we arrive at a particular recommendation on nitrogen valve, so you can follow the reasoning yourself. On nitrogen valve we include start up and shutdown, because that is where the heaviest loading occurs. With nitrogen valve the seat is the component that determines performance, and the body is rarely the limiting factor. Our customers work in chemicals, petrochemicals, pharmaceuticals, power generation, offshore and in hydrogen and ammonia projects.
What should I watch technically on nitrogen valve?
Applications run from air separation and gas distribution to blanketing in chemical plants and purging during maintenance. In technical gases the subject is oxygen, nitrogen, argon, hydrogen and mixtures, each with its own cleanliness and safety requirements. Chemicals and petrochemicals bring the widest variety of media and therefore the most bespoke questions. In pharmaceutical and food production the drivers are cleanliness, flushability and demonstrable material traceability. The answer on nitrogen valve depends strongly on operating conditions, which is why we always ask for those first. On nitrogen valve we prefer a well founded answer to a fast one that turns out to be wrong later. We see demand for nitrogen valve rising in hydrogen and ammonia projects, where tightness requirements are high. What defines us is that we would rather spend an extra half hour on the specification than ship the wrong valve that comes back two months later.
We keep spare parts and overhaul kits mapped per project, so that a breakdown does not start with a search from scratch. If you have an existing tag plate or serial number, send it along, because that lets us work directly from the original configuration. On repeat orders we record the configuration, so a follow up delivery is identical to the first and installation holds no surprises. A P&ID, a datasheet or even a photograph of the existing installation often helps us faster than a long description. This is one of the points on nitrogen valve where suppliers differ most clearly from one another. The answer to this question on nitrogen valve changes as soon as the medium or the temperature changes. We handle an enquiry for nitrogen valve on its technical merits rather than as a price request that only produces a number. Call +31 (0)70-2210560 or send your specification to sales@dutchvalvevision.com and we will pick it up.
Lead times depend on the execution, because a standard size from a running series behaves very differently from a valve in an exotic alloy with NACE certification. For shutdowns and turnarounds we look at accelerated routes, and in those cases we are honest up front about what is and is not achievable. We quote a realistic lead time rather than an optimistic one, because a missed delivery date costs more than an extra week in the planning. Documentation such as material certificates, test reports and declarations is supplied as standard, matched to what the project requires. We always explain why we arrive at a particular recommendation on nitrogen valve, so you can follow the reasoning yourself. On nitrogen valve we include start up and shutdown, because that is where the heaviest loading occurs. A tag plate with project data belongs with nitrogen valve as standard where the project requires it. We work as a technical supplier rather than a catalogue reseller, which means we carry out the selection ourselves on the basis of medium, pressure, temperature and code requirements.
For an accurate quotation we need the nominal diameter, the pressure class, the medium, the operating temperature and the required actuation. We come back with a proposal that explains why we recommend a particular execution, including the alternatives we considered. Please also state the connection standard, the required leakage class and any project requirements such as NACE, PED or ATEX. For shutdowns and turnarounds we look at accelerated routes, and in those cases we are honest up front about what is and is not achievable. We see this come back regularly in enquiries about nitrogen valve, and the answer is rarely a single sentence. For nitrogen valve a good specification up front is cheaper than a correction afterwards. Even when the specification for nitrogen valve is not yet finalised, you can bring the question to us. You can reach us on +31 (0)70-2210560 and at sales@dutchvalvevision.com, and our office hours are Monday to Friday from 09:00 to 17:00.