Neometrix / Vacuum & Gas Systems / High-Vacuum Pumping Station / NMX-HVP-89

NMX-HVP-89 · ENGINEERED-TO-ORDER CLASS — SURVEY · SIZE THE LINE · CHOOSE THE PUMPS · INTERLOCK · BUILD · PROVE

High-Vacuum Pumping Station. The pipe sets the speed.

Name: High-Vacuum Pumping Station
Brand: Neometrix
SKU: NMX-HVP-89

A high-vacuum pumping station takes a chamber from atmosphere down to a high vacuum and holds it there. It is a roughing pump, a turbomolecular pump on a backing pump, a gate valve, gauges and a controller, on one frame. Neometrix engineers it as a system around the customer's chamber: the pipe to it, the order of the pumps, the valves, the interlock and the proof.

So the station has to reach the chamber through a short, wide pipe, start its pumps in the right order, and close the chamber off when anything goes wrong.

Discuss a high-vacuum pumping station Capability note (PDF)

A trolley-mounted high-vacuum pumping station on a plain white studio background: a rigid pale grey steel frame on four castor wheels carrying an upright stainless turbomolecular pump with a round flange on its top, a pale grey backing pump on the lower shelf joined to it by a flexible stainless hose, a blank pale grey controller box on the frame and a stainless handle, and no people

Fig · 01 — A trolley-mounted pumping station: a turbomolecular pump with its flange ready for the chamber, a backing pump on the shelf below, and a controller, on one frame — illustrative render.

The result

a chamber at high vacuumheld there, and read truly

The line

short, wide and straightwith the pump close to the chamber

The pumps

roughed first, then the turboon a backing pump that keeps its outlet low

The safety

closed off on any faultgate valve, gauges and a slow dry vent

Status

engineered to orderno delivered installation claimed

ISO 9001ISO 14001ISO 3529-1 reference vocabulary

Overview

Why the pump is the easy part, and the pipe and the order decide the result.

Because a large pump on a long, thin line sees the chamber only through that line, and the line is the slower of the two.

A pumped vacuum chamber on a plain white studio background: a squat upright brushed stainless cylinder with a domed top on three short legs, a short wide straight stainless pipe dropping from its underside into a stainless valve housing and a stainless turbomolecular pump in one vertical line, a slim stainless gauge tube branching from the chamber side to a plain small cylindrical gauge head, clamp rings on every joint, and no people

Fig · 02 — The pump close under the chamber: a short, wide, straight pipe to a gate valve and a turbomolecular pump, so that the pipe takes little of the speed — illustrative render.

The pipe sets the speed.

What the station is for

It pumps down a chamber that has to run in a high vacuum: a coating or thin-film process, a surface-science experiment, an instrument or a detector, a part that is being outgassed or leak-checked. It takes the air out, keeps it out, and tells the operator the truth about the pressure.

Why the pipe sets the speed

The speed at the chamber is the speed of the pump in series with the conductance of the pipe between them, so it is always below both. A long, thin pipe throttles a large pump, and a short, wide one lets a smaller pump do the job. So the pump goes close to the chamber and the line is straight and wide.

Why the pumps run in order

A turbomolecular pump cannot start against atmosphere. A roughing pump takes the chamber down first, the turbomolecular pump is started, and a backing pump holds its outlet low. One backing pump often does both jobs, through a roughing valve and a foreline valve.

Why the backing pump is chosen with care

An oil-sealed pump can send oil vapour back toward the chamber. A dry pump cannot. So a dry backing pump is chosen where the chamber has to stay clean, and a trap is fitted where oil is used.

Why the gauges are chosen for the range

A thermal gauge reads the rough range, and an ionisation or cold-cathode gauge reads the high range. A combination gauge joins them. A gauge reads differently for different gases, so a reading is a reading and not a proof.

Why the station is interlocked

A power failure, a stopping pump or a rising pressure must close the chamber off and not spoil it. So the gate valve closes by itself, the gauges permit each step, and nothing opens until the pressure says it may.

Why the vent is slow and dry

Letting room air into a chamber puts water on its walls, and water is what slows the next pump-down. So the vent uses dry gas through a restrictor, and waits for the turbomolecular pump to slow as its maker states.

Why the proof is a curve and a test

A leak keeps the pressure rising at a steady rate. A surface giving off gas rises more slowly, and slows further. So the station is proved by the pump-down curve and by a rate-of-rise test, and the record goes with it.

The method

Survey, size the line, choose the pumps, interlock, build and prove.

Six steps in a fixed order. The line and the proof are the two that a quick job skips.

1 · Survey

The chamber, its surfaces, the gases and the process are noted, with the pressure the work needs and how soon it has to be reached.

2 · Size the line

The pipe from the chamber to the pump is drawn first, as short, wide and straight as the layout allows, with the fewest bends and valves in it, because it sets the speed.

3 · Choose the pumps

A turbomolecular pump, a backing pump and the valves are chosen for the gas load and for the cleanliness the chamber needs, dry or oil-sealed, with a trap where oil is used.

4 · Interlock

A controller starts the pumps in order, opens the gate valve only when the pressure permits, closes it on any fault, and vents slowly and dry.

5 · Build

The frame, the pipework and the flanges are built from clean parts, with the right seal for each joint, and the line is leak-checked before the pumps are joined to it.

6 · Prove

The pump-down is recorded, a rate-of-rise test is run, the interlock is exercised, power failure included, and the record is handed over with the station.

Which pump, which job

Pump	How it works	What to watch
Oil-sealed rotary vane pump	traps gas between vanes and an oil film and pushes it out	oil vapour can drift back toward the chamber, so it needs a trap or a chamber that can take it
Dry scroll pump	moves gas along between two scrolls, with no oil	clean, but its tips wear, and it does not reach quite as far as an oil-sealed pump
Diaphragm pump	flexes a membrane to move the gas, with no oil	dry and quiet, but it reaches only a modest vacuum, so it suits a small turbomolecular pump
Turbomolecular pump (this page)	spinning blades knock the gas toward the outlet	it needs a backing pump, and it must not be vented or knocked while it spins fast
Ion or cryogenic pump	holds the gas on a surface instead of moving it out	it fills up, so it is used for ultra-high vacuum and needs regenerating or replacing

The step people underrate is the line. Narrow it a little and the pumping falls a great deal, because the conductance goes with the cube of the width.

Work content

What the station contains, element by element.

Read it as a checklist: a station missing a row will pump, but it will not reach the vacuum, or keep the chamber safe when something fails.

A complete pumped high-vacuum system on a plain white studio background: a plain stainless cylindrical chamber on a pale grey steel frame, a short wide stainless pipe from its underside to a gate valve and a turbomolecular pump, a flexible stainless hose from the pump along the floor to a pale grey dry backing pump in a plain housing, and a blank pale grey controller box on a slim post, and no people

Fig · 03 — The whole system: the chamber, the short wide pipe, the gate valve and the turbomolecular pump, the foreline to the backing pump, and the controller — illustrative render.

Element	What it does	What matters
Turbomolecular pump	takes the chamber from a rough vacuum to a high vacuum	chosen for the gases and for the speed the line allows, started only after roughing, and not vented while it spins fast
Backing pump	keeps the outlet of the turbomolecular pump low, and does the roughing	dry where the chamber has to stay clean, or oil-sealed with a trap
Valves	rough the chamber, back the pump and shut the chamber off	the gate valve closes by itself on a fault, and each valve and seal is chosen for the vacuum it holds
Pipework and flanges	carry the gas from the chamber to the pump	short, wide and straight, smooth inside, with clamped or bolted flanges and the right seal for each joint
Gauges	read the pressure	a thermal gauge for the rough range and an ionisation or cold-cathode gauge for the high range, placed where they read the chamber and not the pump
Vent valve and restrictor	let the chamber back to atmosphere	dry gas, slowly, and not until the turbomolecular pump has slowed
Bakeout	drives water and gas off the walls	for ultra-high vacuum: heaters and jackets, and a controller that holds the temperature
Frame or trolley	carries the parts	rigid, with the vibration of the pumps kept from the chamber and the gauges, and a clear route for hoses and cables
Controller and interlock	run the station and keep it safe	starts the pumps in order, permits each step from the gauges, and closes the chamber off on a fault or a power loss
Cooling and supplies	keep the pumps within their limits	cooling where the pump needs it, and clean power with a safe stop
Procedure and record	fix the start, the stop, the vent and the proof	the same for every station, with the pump-down on record
Testing & documentation	prove the station first	the line leak-checked, the pump-down recorded, a rate-of-rise test, the interlock and a power failure exercised, and a record the customer can inspect

The elements that decide the result are the line and the order of the pumps, and the one that decides whether the chamber stays safe is the interlock. The first two bring the chamber to its vacuum, and the third closes it off when something fails.

Full specification — expand

System	A turbomolecular pump on a backing pump, dry or oil-sealed; a roughing line and a foreline valve; a gate valve to the chamber; a thermal gauge and a high-vacuum gauge, or a combination gauge; a vent valve with a restrictor and dry gas; a rigid frame with clamped or bolted flanges; bakeout heating where the vacuum needs it; a controller with an interlock; a written procedure; a pump-down record; and testing and documentation before handover
The One Idea	The pipe sets the speed.
Why The Pipe Sets The Speed	The speed at the chamber is the speed of the pump in series with the conductance of the pipe between them, so it is always below both; the conductance of a long tube rises with the cube of its diameter and falls with its length, so a short, wide, straight line is worth more than a bigger pump on a long, thin one
Why The Pumps Run In Order	A turbomolecular pump cannot start against atmosphere: a roughing pump takes the chamber down first, the turbomolecular pump is started, and a backing pump holds its outlet low; one backing pump often does both jobs through a roughing valve and a foreline valve
Why The Station Is Interlocked	A power failure, a stopping pump or a rising pressure must close the chamber off and not spoil it, so the gate valve closes by itself, the gauges permit each step, and the vent is slow and dry
Standards	ISO 3529-1 covers the vocabulary of vacuum technology and ISO 2861 covers clamped quick-release couplings, the clamped joint used on small vacuum flanges. This page prints none of their dimensions or limits, and no edition year: those come from the standard the customer names. Approval of a station rests with the customer and the authority they name; none is claimed here
Configurations	A trolley-mounted station, a rack-mounted station for a fixed chamber, and a station for ultra-high vacuum
Scope Boundary	This page is the high-vacuum pumping station, which takes a chamber to a high vacuum and holds it there. It is not a thermal vacuum chamber, which is the chamber with its thermal shrouds (see thermal vacuum chamber), not a helium leak detection system, which finds a leak with a tracer gas (see helium leak detection system) and not a hypobaric altitude chamber, which holds a low pressure for people (see hypobaric altitude chamber). It does not cure a leak or a chamber that gives off gas: it shows them. It does not make a flammable or reactive gas safe to pump: that needs its own design. No certification or accreditation is claimed here
Status	Neometrix has quoted against successive high-vacuum pumping station requirements, and no delivered high-vacuum pumping station is claimed.

Configurations

One method, three ways to build the station.

The method, the line, the order of the pumps and the proof are shared. What changes is where the chamber stands and how clean the vacuum has to be.

Trolley-mounted station

A turbomolecular pump and a backing pump on wheels, for one chamber or a few

For a laboratory with more than one chamber: the station rolls to the chamber, joins it by one wide flange and a gate valve, and pumps it down.

Rack-mounted station for a fixed chamber

Built around the chamber, with the pump close under it

For a chamber that stays where it is: the pump on a short wide pipe, a gate valve, the gauges, the vent and the controller on one frame, interlocked with the process.

Station for ultra-high vacuum

For work that needs the cleanest vacuum, with bakeout and a pump that holds it

For ultra-high vacuum: metal-sealed flanges, bakeout heating and its controller, and an ion or cryogenic pump to hold the vacuum once it has been reached.

And the part that is not equipment at all, yet decides all three: the survey and the test plan. They fix the chamber, the line to it, the gases, the order of the pumps and the checks at handover. They are written from the customer's own chamber and process, not from the pump.

The drawings

A reference set, drawn as real CAD sheets.

Two sheets of one reference configuration: the process and instrument schematic of a high-vacuum pumping station, and its general arrangement with three details. They show the chamber, the short wide line, the pumps, the gauges, the vent and the interlock, the pipe that sets the speed, the pumping order and the clamped joint. They carry tags and letters only. Every pressure, speed, flow and size is fixed by design for the customer's chamber and process.

Reference drawing sheet one, the process and instrument schematic of a high-vacuum pumping station. A pumping station controller sits above a vacuum chamber with two gauges on its top and a vent on its side, the vent taking dry gas through a valve and a restrictor. A short, wide, straight line leads from the chamber through a gate valve to a turbomolecular pump, which discharges through a foreline valve to a foreline with a pressure gauge, an oil trap and a backing pump that exhausts to a safe place. A roughing line with a roughing valve runs from the chamber to the foreline. Every valve is drawn closed without power. A legend, a table of holds and releases, ten notes and a title block stamped reference configuration, not for construction

Fig · 04 — Sheet 01, the process and instrument schematic: the chamber, the short wide line, the turbomolecular and backing pumps, the gauges, the vent and what holds or releases the sequence. Reference configuration, tags only.

Reference drawing sheet two, the general arrangement and details of a high-vacuum pumping station. An elevation of a rack-mounted station shows a chamber on a frame, a short wide line dropping through a gate valve to a turbomolecular pump, a foreline hose to a backing pump on the floor, a controller cabinet, a gauge and a vent valve, with dimension letters for the length and diameter of the line. A plan shows a trolley-mounted station with its turbomolecular pump, backing pump, controller and castors, with dimension letters for its width and depth. An item list numbers ten parts. Detail A compares a short, wide, straight line with a long, thin, bent one. Detail B is a table of valve states for roughing, starting, running and venting. Detail C is a section through a clamped joint with a centring ring and a seal. A title block stamped reference configuration, not for construction

Fig · 05 — Sheet 02, the general arrangement and details: the station in elevation and plan, the pipe that sets the speed, the pumping order and the clamped joint. Reference configuration, letters only.

Every real station is drawn for its own chamber, gases and site. These sheets are the arrangement and the order of control that a project set starts from. Approval of any drawing rests with the customer and the authority they name; none is claimed here.

PDF · two sheets

Reference drawings — schematic and arrangement

PDF · capability sheet

High-vacuum pumping station — what Neometrix engineers

Where it is used

Wherever a chamber has to run in a high vacuum, and the pressure has to be right.

The common thread is a chamber that has to be clean, a vacuum that has to be reached on time, and a reading that has to be trusted.

Coating and thin-film development

Where a chamber has to be clean and at high vacuum before a layer is made.

Surface-science and materials laboratories

Where the chamber is the experiment, and the pressure has to be known and steady.

Instrument and detector builders

Where an assembly has to run, or be tested, in vacuum.

Test and conditioning rooms

Where parts are outgassed, leak-checked or run in vacuum before they are used.

Watch

See it in motion.

A short walkthrough video of the high.

FAQ

Common questions.

Longer answers, for readers who want the reasoning.

Q · 01 What does a high-vacuum pumping station actually do?

It takes a chamber from atmosphere to a high vacuum and holds it there. A roughing pump takes most of the air out first. A turbomolecular pump then takes the chamber the rest of the way, on a backing pump that keeps its outlet low. A gate valve joins it to the chamber, gauges read the pressure, a vent lets the air back in, and a controller runs the sequence and closes the chamber off on a fault. It does not decide what pressure a process needs or what gas it may use: those come from the customer's own work, and the station holds to them.

Q · 02 Why does the pipe to the chamber matter so much?

Because the speed at the chamber is the speed of the pump in series with the conductance of the pipe between them, and a series pair is always below both. At high vacuum the conductance of a long tube rises with the cube of its diameter and falls with its length, so a narrow or long line throttles even a very large pump. A short, wide, straight line does the opposite: it lets a smaller pump do what a larger one cannot. Every bend, valve and reducer in the line adds resistance. So the survey draws the line first, and the pump goes where the line is shortest.

Q · 03 Why a backing pump, and why not start the turbomolecular pump at once?

A turbomolecular pump works only when the gas is thin enough for its blades to push single molecules, so it cannot start against atmosphere. A roughing pump takes the chamber down first. The turbomolecular pump is then started, and a backing pump holds its outlet at a pressure it can work against. One backing pump often does both jobs, through a roughing valve and a foreline valve. The choice of backing pump matters too. An oil-sealed pump reaches a little further, but it can send oil vapour back toward the chamber. A dry scroll or diaphragm pump cannot, so it is chosen where the chamber has to stay clean.

Q · 04 Why the gate valve, the gauges and the interlock?

Because the things that go wrong are quick and the harm is slow to undo. A power failure, a pump that stops or a pressure that rises can let air or oil into a clean chamber, or put a spinning rotor at risk. So the gate valve closes by itself, and the gauges permit each step: the foreline valve opens only when the roughing has done its work, the turbomolecular pump starts only when the pressure allows, and the gate valve opens only when the pump is up to speed. The vent is slow and dry, because room air puts water on the walls and water is what slows the next pump-down. The interlock is what makes a mistake cost a restart and not a ruined chamber.

Q · 05 Is this the same as the thermal vacuum chamber, the helium leak detection system or the hypobaric altitude chamber?

No, and the differences are worth stating precisely. The thermal vacuum chamber page covers the chamber with its thermal shrouds. The helium leak detection system page covers finding a leak with a tracer gas. The hypobaric altitude chamber page covers a chamber that holds a low pressure for people. This page is the high-vacuum pumping station, which takes a chamber to a high vacuum and holds it there. It does not replace any of them, and it does not claim what they claim a second time.

Q · 06 Has Neometrix built one of these?

We would rather answer this plainly than let a page imply otherwise. Neometrix has quoted against successive high-vacuum pumping station requirements, and no delivered high-vacuum pumping station is claimed. What stands behind the offer is adjacent: Neometrix engineers a thermal vacuum chamber (see the thermal vacuum chamber page), a helium leak detection system (see the helium leak detection system page) and a hypobaric altitude chamber (see the hypobaric altitude chamber page). The pumps, valves, gauges, flanges and controller parts are catalogue items, bought in, not invented. What Neometrix engineers is the system around them: the survey, the line to the chamber, the choice and order of the pumps, the valves, the frame, the interlock, the procedure and the record. So the honest position is that the station is engineered to order, the neighbouring disciplines are in the building, and the first station of this exact kind will be built around the customer's own chamber rather than taken off a shelf.

Q · 07 Which standard applies, and what can the station not do?

ISO 3529-1 covers the vocabulary of vacuum technology and ISO 2861 covers clamped quick-release couplings, the clamped joint used on small vacuum flanges. This page prints none of their dimensions or limits, and no edition year: those come from the standard the customer names. The station takes a chamber to a high vacuum and holds it there. It does not cure a leak or a chamber that gives off gas, it only shows them, it does not make a flammable or reactive gas safe to pump, which needs its own design, and it does not replace the customer's own vacuum and safety checks: this page claims no certification or accreditation. No pressure, speed, flow, size or quantity figure is printed here, and approval for use rests with the customer and the authority they name; none is claimed here.

Q · 08 What do you need from us to quote?

Six things, and most of them describe your chamber rather than the station. First, the chamber: its size, its surfaces and its ports, and where it stands. Second, the gases: what the process puts into the chamber, and whether any of it is flammable, reactive or corrosive. Third, the vacuum: the pressure the work needs and how soon it has to be reached. Fourth, the process: what happens if the vacuum is lost, and whether it can be stopped. Fifth, the supplies: power, cooling and a dry gas for the vent. Sixth, the record: what you want kept for each pump-down. From that we come back with a station concept, a written test plan you can check, and a budgetary price.

The neighbouring pages, and how they differ from this one.

Three neighbours: one is the chamber, one finds a leak, one holds a low pressure for people.

↗ The chamber

Thermal Vacuum Chamber

The chamber with its thermal shrouds - where this page is the pumping station that takes a chamber to a high vacuum.

↗ Finding a leak

Helium Leak Detection System

Finds a leak with a tracer gas - the test that shows whether a chamber will hold the vacuum this page pumps it down to.

↗ A low pressure

Hypobaric Altitude Chamber

Holds a low pressure for people - a different job from taking a small chamber to a high vacuum.

Browse all Neometrix product lines.

Get a quotation

Tell us the chamber,
and the vacuum it needs.

The projects desk replies within two working days with a station concept, a written test plan you can check, and a budgetary quotation. Write to [email protected] or use the form.

Enquire — high-vacuum pumping station Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 ENGINEERED-TO-ORDER CLASS — HIGH-VACUUM PUMPING STATION SURVEY · SIZE THE LINE · CHOOSE THE PUMPS · INTERLOCK · BUILD · PROVE — THE PIPE SETS THE SPEED ENGINEERED IN NOIDA · INDIA