Plumbing
Laboratory and process vacuum system field guide
Design the house vacuum system around what the pipe actually carries: liquid and vapor. Slope to a fluid trap, pick the pump for the chemistry and the vacuum level, exhaust outside, and keep it clear of certified medical vacuum.
Direct answer
A laboratory or process vacuum system is the central setup that pulls vacuum from one or more pumps through piping to inlets at the benches, fume hoods, and process equipment for filtration, aspiration, and evaporation. It is not certified medical vacuum. The adopted code, the process, and the pump manufacturer control the design.
Key takeaways
- Lab and process vacuum follows the plumbing or mechanical code; certified medical-surgical vacuum follows NFPA 99 and ASSE-certified install, and the two are never cross-connected.
- Lab vacuum pulls liquid and vapor, not just air, so slope every run to a low-point fluid trap or the liquid destroys the pump.
- Size on simultaneous demand, not total inlet count: about 1 SCFM per inlet with a diversity factor, read at the operating vacuum level.
- Pump families: oil-sealed rotary vane reaches around 1 torr, dry claw/scroll pull medium vacuum with no oil mist, liquid-ring handles wet, corrosive, or flammable streams.
- Test with a vacuum decay (leak) test since systems leak inward, then verify vacuum at the far inlet under design flow; exhaust always routes outside.
What a lab or process vacuum system is
A laboratory or process vacuum system is the central plumbing that pulls a vacuum from one or more pumps, through piping, out to inlets at the benches, the fume hoods, and the process equipment. The lab uses that vacuum to pull liquid through a filter, to aspirate a flask, to run a rotary evaporator, or to drive a process step. One pump in a mechanical room serves a whole floor of outlets, the same way a single compressor serves a shop full of air drops.
That central arrangement is the alternative to a small pump sitting on the bench next to each apparatus. A benchtop pump is simple and it belongs to one user. A house system trades that simplicity for fewer machines, less noise in the lab, and one exhaust point you can run outside. The cost is that everyone on the line shares the same vacuum, so what one user does at one hood moves the reading at the hood down the hall.
What separates this from ordinary plumbing is what travels in the pipe. Lab vacuum pulls liquid and vapor, not just air. Solvent, water, acid, whatever was in the flask gets carried toward the pump unless something stops it. Design the system as if it will see liquid, because it will.
What is the difference between lab and medical vacuum?
Laboratory and process vacuum serves research and industrial work. Medical-surgical vacuum serves patient care, and it is a different system under a different code. The two look alike on a drawing, a pump, a receiver, and piping to inlets, but they are not interchangeable and you do not pipe one off the other.
Medical-surgical vacuum is governed by NFPA 99, the Health Care Facilities Code. It is installed by ASSE-certified personnel, brazed in clean copper, and verified by an independent third party before any of it is used on a patient. The medical gas piping guide covers that work in full. Lab and process vacuum carries no such certification requirement in most jurisdictions. It follows the plumbing or mechanical code and the manufacturer's design, and it is sized and built for the lab, not the operating room.
The distinction matters because mixing them is a serious mistake. If an outlet feeds patient care, it is medical vacuum and it gets the NFPA 99 treatment, full stop. A research bench, a fume hood, a process skid is lab vacuum. When a project has both, they stay separate systems with separate pumps and separate piping, and the line between them is not a judgment call you make in the field.
The parts of a central vacuum system
A central vacuum system is a chain, and every link has a job. Walk it from the lab back to the pump and you can troubleshoot almost anything that goes wrong with it.
The inlet at the bench or hood is where the user connects and draws vacuum. The piping carries that vacuum back through the building, sloped so any liquid it picks up runs toward a low point instead of toward the machine. A fluid trap or separator sits ahead of the pump to knock liquid out of the airstream before it arrives. A receiver tank on the suction side smooths demand so the pump is not chasing every flask someone opens. The pump, or a pair of pumps, does the work of pulling the vacuum. The exhaust takes whatever the pump discharges, air, vapor, and on an oil-sealed pump a fine oil mist, out of the building.
Lose any one link and the others cannot cover for it. A perfect pump behind a flat, untrapped run still drinks liquid and dies. A good trap behind an exhaust dumped indoors still fills the mechanical room with fumes. The system works as a chain or not at all.
What type of vacuum pump is used in a lab?
The common lab vacuum pumps are oil-sealed rotary vane, dry pumps such as claw and scroll, and liquid-ring pumps. Which one fits depends on the vacuum level you need and what is going to be in the gas stream. There is no single right pump for every lab. A pump that is ideal for a clean filtration bench is the wrong choice for a header full of solvent vapor.
Oil-sealed rotary vane is the traditional workhorse. The oil seals the clearances so the pump reaches a deep vacuum, down around 1 torr or lower on the better units. Dry pumps, claw and scroll, use no oil in the pumping chamber, so there is nothing to contaminate and nothing to change. They pull a medium vacuum, which covers most house-vacuum duty. Liquid-ring pumps use a ring of liquid as the seal, which lets them swallow slugs of water and handle corrosive and flammable vapor that would wreck the other two.
The selection is an engineering and manufacturer call, not a rule of thumb. Match the pump to the vacuum level, the flow, and the chemistry of what it pumps, then confirm it against the manufacturer's curves and the project requirements before you commit.
Oil-sealed, dry, and liquid-ring pumps compared
The three pump families split along two lines: how deep a vacuum they pull, and how they tolerate what is in the gas.
Oil-sealed rotary vane goes deepest and costs the least to buy, but the oil is the catch. Pump water or solvent vapor and the oil thickens, emulsifies, and stops sealing, so the pump needs gas ballast, regular oil changes, and a real trap ahead of it or it dies young. Dry pumps cost more up front and may not pull quite as deep, but with no oil there is nothing to emulsify, nothing to mist into the exhaust, and far less to service. That is why clean labs and any place oil mist is unacceptable lean dry. Liquid-ring is the choice when the stream is wet or corrosive. The sealing liquid, usually water, absorbs the heat and carries the slug through, and the pump body can be specified in stainless or another resistant material for aggressive chemistry. The trade is a shallower vacuum and the job of managing the seal liquid.
Read the comparison as a starting point, not a spec. The right answer for a given lab comes out of the vacuum level, the flow, the chemistry, and the manufacturer's data.
| Pump type | Vacuum reach | Best fit | Watch out for |
|---|---|---|---|
| Oil-sealed rotary vane | Deep (around 1 torr or lower) | Clean, dry gas needing deep vacuum | Oil emulsifies on vapor; needs ballast, oil changes, a trap |
| Dry (claw, scroll) | Medium vacuum | Clean labs, no oil mist, low maintenance | Higher first cost; tip seals wear |
| Liquid-ring | Shallower vacuum | Wet, corrosive, or flammable streams | Manage seal liquid; less depth |
How much vacuum does a lab system pull?
House or rough vacuum runs in the range you can read on a gauge in inches of mercury, up to roughly 25 inHg of vacuum for typical bench work, and that covers filtration, aspiration, and most general lab use. Deep process vacuum is a different regime, measured in torr or microns, where the numbers get too small to read in inches of mercury at all.
The unit tells you which regime you are in. Rough vacuum is the inches-of-mercury range, from atmospheric at about 29.92 inHg down toward the low end a gauge can resolve. Below that, the trade switches to absolute units: 1 torr is 1 millimeter of mercury, and 1 micron is one-thousandth of a torr. There are about 25,400 microns in an inch of mercury, which is why nobody tries to read deep vacuum on an inHg gauge.
Most central house systems live in the rough range, and that is all the bench needs. When a process calls for deep vacuum, freeze-drying, vacuum distillation, a vacuum oven, that load usually gets its own dedicated pump sized for the level, not a tap off the house line. Pulling deep vacuum through a long shared header rarely works, and it drags the whole system down for everyone else on it.
How do you size a lab vacuum system?
Size a lab vacuum system on the number of inlets that run at once, not the total count, because lab vacuum is intermittent. A common basis is around 1 SCFM per inlet with a diversity factor applied, since not every outlet is open at the same moment. That is the opposite of medical-surgical vacuum, where the surgical areas get no diversity and a higher per-inlet flow, because in surgery you assume every station can be in use at once.
Three numbers settle the design. First, the flow in standard cubic feet per minute the system has to move at the design vacuum, which comes from the inlet count, the per-inlet demand, and the diversity. Second, the vacuum level itself, because a pump's flow falls off as the vacuum deepens, so the rating has to be read at your operating point, not at free air. Third, the pipe size, large enough that friction loss along the longest run does not starve the far inlet.
Diversity is where judgment lives. A teaching lab with thirty benches rarely sees more than a handful pulling at once. A production line where every station runs continuously sees almost no diversity at all. Size for how the space is actually used, lean toward the heavier case when you are unsure, and confirm the selection against the manufacturer's curves and the project requirements.
Piping materials for lab and process vacuum
Pick the pipe for the process, not out of habit. Copper, including the medical-type copper used on certified systems, is clean and common for general lab vacuum. PVC and CPVC show up on rough house-vacuum lines where the chemistry is mild and the budget is tight. Stainless steel is the choice when the stream is corrosive or the process demands it, and pharmaceutical and aggressive-chemistry labs often specify it.
Two cautions earn their place here. Lab vacuum piping is not the brazed, oxygen-clean, nitrogen-purged copper of a medical system unless it is in fact a medical system. Holding lab vacuum to that standard wastes money; holding medical vacuum to the lab standard is dangerous. And plastic has limits. It can build static, it gets brittle with age, and a long list of solvents attack it, so PVC and CPVC are fine for a mild filtration line and wrong for a header that sees solvent vapor.
Whatever the material, the joints have to hold a vacuum, which is a different test than holding pressure. A joint can pass a pressure check and still leak inward under vacuum. The material list and the joining method belong to the project specification and the manufacturer, so confirm both before the first length goes up.
| Material | Typical use | Note |
|---|---|---|
| Copper (incl. medical-type) | General lab vacuum, clean service | Common and clean; not brazed/purged unless it is a medical system |
| PVC / CPVC | Rough house vacuum, mild chemistry | Static and solvent attack; wrong for solvent vapor |
| Stainless steel | Corrosive or demanding process | Specified where chemistry or process requires it |
Slope the piping and protect the pump
This is the part that ruins pumps, so it gets the emphasis: lab vacuum pulls liquid, and liquid that reaches the pump destroys it. Slope every horizontal run back toward a low point with a fluid trap, so anything the system picks up, condensate or a flask someone sucked dry, drains to where you can catch it instead of riding the airstream into the machine.
The mechanism is simple and unforgiving. Someone aspirates a flask, the liquid gets pulled into the inlet, and now it is in the pipe. If the run slopes the wrong way or sits dead level, that liquid travels with the vacuum straight to the pump. In an oil-sealed pump it emulsifies the oil and the pump loses its seal in days. In any pump a real slug can hydro-lock it. Slope and a trap are not optional refinements. They are the difference between a pump that lasts years and one that fails in a month.
Pitch the mains and branches consistently toward the trap, the way you would slope a drain, and put the low point and the trap where someone can actually reach them. A trap nobody can get to is a trap nobody empties.
The fluid trap and separator
The fluid trap, sometimes called a knockout pot or moisture separator, is the vessel that catches liquid before it reaches the pump. It is the single component that protects the machine, and on a central system one sits at the low point of the piping and another right at the pump suction.
It works by giving the airstream somewhere to slow down and drop its load. Velocity falls inside the vessel, the liquid falls out and collects in the bottom, and dry air carries on to the pump. The trap needs a way to be drained or emptied, a sight level or a high-level alarm on a system that matters, and a filter element where the application calls for one. At the bench, users add their own small trap in the line, the classic vacuum flask, so the worst of the liquid never even reaches the house piping.
Treat the trap as a maintenance item, not a fixture. It fills. When it fills past what it can hold and nobody has emptied it, the liquid goes exactly where you spent all that effort keeping it out. Check it, drain it, and put it on the PM schedule.
Exhaust to the outside
A vacuum pump discharges everything it pulls, and on a lab system that discharge is not clean room air. It carries solvent vapor, whatever was aspirated, and on an oil-sealed pump a fine oil mist. That exhaust goes outside, routed and terminated where the code and the lab's ventilation design require, not dumped into the mechanical room.
Run the exhaust indoors and you have moved the lab's fumes into the building and coated the equipment room in oil mist. On corrosive or hazardous streams it is worse, because now you are venting that chemistry where people work. The discharge piping has to handle the chemistry and the heat, slope so condensate drains back to a point you can manage rather than into the pump, and carry an exhaust filter or oil-mist eliminator where the pump type and the process call for one.
Where the exhaust ties into the building's fume exhaust or runs as its own stack is a design decision driven by the chemistry and the local code. Confirm it with the mechanical engineer and the AHJ. This is not the place to improvise a termination.
Inlets, valves, and bench traps
The inlet is what the user sees, and on a lab system it is usually a vacuum service fixture at the bench or in the fume hood, often a petcock or needle valve the user opens to draw vacuum. It gives control at the point of use and isolates that station when it is closed.
A few things keep the inlets working. Each one wants a local shutoff so a station can be serviced without killing the whole line, and the layout should let a user throttle vacuum without slamming the demand onto the pump. At the inlet, a bench-top trap, the vacuum flask between the apparatus and the wall, is the user's own defense against pulling liquid into the house piping. It is the first line of the slope-and-trap principle, and it is the one users actually control.
Label the inlets for what they are. A vacuum outlet that looks like an air or gas outlet invites the cross-connection the whole layout is supposed to prevent.
How do you handle corrosive or flammable vapor?
When the stream is corrosive, condensable, or flammable, the standard oil-sealed pump and an ordinary trap are not enough, and forcing them anyway is how you get a failed pump or worse. Match the equipment to the chemistry. A liquid-ring pump tolerates corrosive and flammable vapor and slugs of liquid that would destroy a dry or oil-sealed pump, which is why it shows up on the aggressive lines.
Corrosive vapor wants resistant materials all the way through: the pump body in stainless or a coated construction, the trap and piping rated for the chemistry, and a filter or scrubber on the exhaust where the discharge needs treatment. Condensable vapor wants a trap that actually drops it out, and on an oil-sealed pump, gas ballast to keep the condensate from collecting in the oil. Flammable vapor raises the stakes again, because a running pump is an ignition source. That is where you look at sealed or purged equipment, explosion-rated motors, and keeping the vapor concentration out of the flammable range, all of it driven by the process safety review and the manufacturer.
None of this is a field guess. Corrosive and flammable service is engineered, specified, and confirmed against the safety data for the actual chemistry. When in doubt, isolate that process onto its own dedicated pump instead of putting it on the shared house line.
Duplex pumps, lead-lag controls, and alarms
A research lab that cannot lose vacuum gets a duplex system: two pumps instead of one, so the line stays up when a pump is down for service or has failed. The controls alternate them in a lead-lag arrangement, where one pump leads and the other starts as lag when demand climbs or the lead cannot hold the setpoint, and the lead role rotates so the two wear evenly.
A vacuum switch senses the level and tells the pumps when to run. On a single pump it cycles the machine to hold the band. On a duplex it runs the lead, brings in the lag on heavy demand, and rotates the assignment over time. An alarm warns when the system cannot hold vacuum, when a pump faults, or when a trap hits high level, so a problem gets attention before the lab finds out by losing its work.
Whether a lab needs duplex is a risk call. A teaching lab can live with a single pump and a planned outage to service it. A line running a continuous experiment or a process that fails the moment vacuum drops cannot, and there the second pump is cheap next to the cost of the loss. Where the application is truly critical, size each pump to carry the design load on its own.
How do you test and commission a lab vacuum system?
Test a lab vacuum system by proving it holds vacuum and delivers it where it has to. The core check is a vacuum decay, sometimes called a leak test: pull the system down to a test level, isolate it from the pump, and watch the gauge over a set time. If the vacuum decays faster than the acceptance criterion, there is a leak, and you find it before the system goes into service.
A vacuum system leaks inward, so a vacuum decay catches what a pressure test can miss, and the two are not the same check. Beyond the decay test, verify the vacuum at the far inlet, the worst-case outlet at the end of the longest run, under the design flow, because that is where an undersized pipe or a marginal pump shows up. A reading that is fine at the pump and weak at the last hood is a sizing or leakage problem, not a pump problem.
Commissioning ties it together. Confirm the pumps stage and alternate as intended, the alarms actually trip, the trap drains, and the exhaust runs where it should. Then record the test vacuum, the decay result, the far-inlet reading, and the acceptance basis. The acceptance numbers and method come from the project specification and the manufacturer, so verify them before you test, not after.
Maintenance that keeps it running
A lab vacuum system fails in predictable ways, and a short PM list heads off most of them. The trap and the oil are the two items that bite first, so they lead the list.
- Change oil-sealed pump oil on the manufacturer's interval, and sooner if it has turned cloudy or thickened, because emulsified oil has already stopped sealing.
- Watch the tip seals or scroll tips on dry pumps, since they wear even though there is no oil to change.
- Change the inlet and exhaust filters before they load up and choke the flow.
- Empty the fluid trap before it fills, and confirm the high-level alarm where one is fitted.
- Check belt tension and wear on belt-driven pumps.
- Read the vacuum at the far inlet periodically, because a slow decline there is the early warning of a developing leak or a tiring pump.
- Confirm the lead-lag rotation and the alarms still function, not just the running pump.
When it is medical vacuum, not lab vacuum
One line decides which code you are under: if the vacuum serves patient care, it is medical-surgical vacuum, built and certified to NFPA 99, not to the lab standard. This is worth saying twice because the systems look alike and the consequences of confusing them do not.
Medical vacuum is brazed clean copper, installed by ASSE-certified personnel, tested by the installer and then verified by an independent third party before anyone uses it. The medical gas piping guide walks through that scope. Lab and process vacuum carries none of that and should not pretend to. The reverse error is the dangerous one. Build a patient-care outlet to lab-vacuum rules and you have an uncertified line serving a patient, which is exactly what NFPA 99 exists to prevent. When a building has both, keep them separate, and never tap a medical outlet off a lab system or a lab outlet off a medical system.
Lab compressed air and process vacuum together
Lab vacuum rarely shows up alone. The same benches and hoods usually get lab compressed air, the companion utility, and the two systems run side by side through the building. Air pushes and vacuum pulls, and the design concerns mirror each other: size for the simultaneous demand, treat what is in the stream, and slope to manage the water. The compressed air piping guide covers the air side, and it pairs with this one on most lab and process jobs.
Process vacuum beyond the lab bench follows the same rules at a larger scale. A plant process skid, a packaging line that pulls vacuum, even a facility or data center process that needs house vacuum, all run on a central pump, a receiver, sloped piping to a trap, and an exhaust outside. The chemistry and the vacuum level change with the process, and the pump is selected to match, but the bones of the system are the ones in this guide.
What to document
A vacuum system nobody documented is a system the next person reverse-engineers with a flashlight. Record what each component is, what it does, and the note that matters for service, so a future tech can read the system instead of guessing at it.
Capture the pump type and model, the design vacuum level and flow, the diversity basis used to size it, the piping material, the trap and exhaust arrangement, and the commissioning results. The table below is the minimum a service tech needs to walk the system and understand why it was built the way it was.
| Component | Function | Note to record |
|---|---|---|
| Pump(s) | Pull the vacuum | Type, model, single or duplex, design vacuum and flow |
| Receiver tank | Smooth the demand | Volume and suction-side location |
| Fluid trap / separator | Protect the pump from liquid | Location, drain method, high-level alarm |
| Piping | Carry the vacuum to inlets | Material, slope direction, low points |
| Inlets | Point of use at bench / hood | Count, valve type, labeling |
| Exhaust | Discharge to outside | Termination, filter or oil-mist eliminator |
| Controls | Stage and protect the system | Vacuum switch setpoints, lead-lag, alarms |
| Commissioning | Prove it holds and delivers | Decay test result, far-inlet reading, acceptance basis |
Common mistakes
- No fluid trap, or piping that does not slope to it, so liquid reaches the pump and ruins it.
- Wrong pump type for a corrosive or condensable stream, so the chemistry attacks the pump or emulsifies the oil.
- Sizing for the total inlet count instead of the simultaneous demand, or ignoring that the pump's flow falls off at the operating vacuum.
- Exhausting oil mist or fumes into the mechanical room instead of outside.
- No redundancy on a research lab that cannot afford to lose vacuum.
- Confusing lab vacuum with certified medical vacuum, or tapping one off the other.
- Skipping the vacuum-decay leak test and trusting a reading taken with no flow.
Field checklist
Want this checklist to run itself on every job — with photo proof and a signed record crews can hand the customer? That's FieldOS.
Standards and references
Lab and process vacuum piping follows the adopted plumbing or mechanical code for the jurisdiction, which governs the materials, the joining, and the support of process and laboratory piping. The exact provisions and the adopted edition vary by jurisdiction and get amended locally, so confirm them against the code the AHJ has actually adopted before you build to a number.
NFPA 99, the Health Care Facilities Code, is the standard that marks the line between this work and medical-surgical vacuum. When the vacuum serves patient care, NFPA 99 and ASSE-certified installation and verification apply, and the system is no longer lab vacuum. Keep that distinction clean. ASSE certifications and laboratory design references inform the rest, but the controlling documents are the project specification and the pump and system manufacturer's data.
Cite the standard that controls the point and let the project specification and the manufacturer override a rule of thumb when they are stricter. Two things carry across every job regardless of the code edition: slope to a fluid trap so liquid never reaches the pump, and pick the pump for the vacuum level and the chemistry, not out of habit.
Units, terms, and conversions
Vacuum gets measured a few different ways, and the same system can read differently across a gauge, a manufacturer sheet, and a process spec, so it helps to keep the conversions straight.
Rough vacuum is read in inches of mercury (inHg), where atmospheric pressure is about 29.92 inHg. Deeper vacuum is read in absolute units: 1 torr equals 1 millimeter of mercury, and 1 micron equals one-thousandth of a torr. There are about 25,400 microns in an inch of mercury. Flow is given in standard cubic feet per minute (SCFM), measured at a reference condition so two pumps can be compared on the same basis. Diversity is the factor that accounts for inlets not all being open at once.
- inHg (inches of mercury)
- Rough-vacuum unit; atmospheric is about 29.92 inHg, and house vacuum reads in this range
- Torr / micron
- Absolute deep-vacuum units; 1 torr is 1 mm of mercury, 1 micron is one-thousandth of a torr
- SCFM
- Standard cubic feet per minute, the flow a pump moves at a reference condition
- Diversity factor
- The reduction applied because not every inlet draws vacuum at the same moment
- Fluid trap / knockout
- Vessel ahead of the pump that drops liquid out of the airstream before it reaches the machine
- Gas ballast
- An air bleed on an oil-sealed pump that keeps condensable vapor from collecting in the oil
- Lead-lag
- Duplex control where one pump leads and the second starts on demand, with the roles rotating
FAQ
What is a laboratory vacuum system?
A laboratory vacuum system is a central setup that pulls vacuum from a pump, through piping, to inlets at the benches, fume hoods, and process equipment. The lab uses it for filtration, aspiration, evaporation, and process steps. One pump in a mechanical room serves many outlets instead of a separate benchtop pump at each apparatus.
What is the difference between lab and medical vacuum?
Lab and process vacuum serves research and industrial work under the plumbing or mechanical code. Medical-surgical vacuum serves patient care under NFPA 99, installed by ASSE-certified personnel and verified by a third party before use. They look alike but are different systems, and you never tap one off the other.
What type of vacuum pump is used in a lab?
Labs use oil-sealed rotary vane pumps for deep vacuum, dry claw or scroll pumps where no oil mist is wanted, and liquid-ring pumps for wet, corrosive, or flammable streams. The choice depends on the vacuum level and the chemistry of the gas, confirmed against the manufacturer's data and the project requirements.
Why does a lab vacuum system need a fluid trap?
Lab vacuum pulls liquid and vapor, not just air, and liquid that reaches the pump destroys it. A fluid trap, set at a low point the piping slopes toward, drops the liquid out of the airstream before it arrives. In an oil-sealed pump, even a little liquid emulsifies the oil and kills the seal within days.
How do you size a lab vacuum system?
Size on the inlets that run at once, not the total, because lab vacuum is intermittent. A common basis is about 1 SCFM per inlet with a diversity factor. Read the pump's flow at the operating vacuum level, not free air, and size the pipe so the far inlet is not starved. Confirm against the manufacturer's curves.
Can you use PVC for a lab vacuum line?
PVC and CPVC work for rough house-vacuum lines with mild chemistry, but they have limits: static buildup, brittleness with age, and attack by many solvents. They are wrong for a header carrying solvent vapor. Copper suits general lab vacuum, and stainless suits corrosive or demanding process. Pick the material for the actual process and verify against the spec.
Why does a lab vacuum pump exhaust have to go outside?
The pump discharges everything it pulls: solvent vapor, aspirated material, and on an oil-sealed pump a fine oil mist. Run that exhaust indoors and you fill the mechanical room with fumes and oil mist, and on corrosive streams you vent that chemistry where people work. Route it outside per the code and the lab's ventilation design.
Do you need duplex pumps on a lab vacuum system?
Duplex is a risk call. A teaching lab can run one pump and take a planned outage to service it. A lab running a continuous experiment, or a process that fails when vacuum drops, needs two pumps in lead-lag so the line stays up during service or failure. Size each pump to carry the load alone where it is critical.
How do you test a lab vacuum system for leaks?
Run a vacuum decay test: pull the system down to a test level, isolate it from the pump, and watch the gauge over a set time against the acceptance criterion. A vacuum system leaks inward, so this catches what a pressure test misses. Then verify the vacuum at the far inlet under design flow and record the results.
People also ask
Codes cited in this guide
This guide is written and reviewed against the published standards below. Always confirm the current adopted edition with the authority having jurisdiction.