Rotary Piston Pumps

​Tuthill’s rotary piston pumps are known for being some of the most rugged, reliable equipment capable of handling especially dirty processes. Tuthill provides a 30-month warranty on all rotary piston pump models.

KT Single-Stage Rotary Piston Pump

  • High pumping capacity at high and low pressures
  • Triplex piston design: dynamically balanced and practically vibration free
  • No metal-to-metal contact between pump piston and cylinder – clearances are filled with oil
  • Quiet running

KT models include an integral, positive pressure lubrication system to insure reliable lubrication at all pressure levels. KT pumps are water-cooled. Optional air-cooling systems are available. Adjustable gas ballast valves are standard for handling water and other vapor loads.

ModelCFM / m3/hHP / kW|Typical Applications
KT-150C150 / 2557.5 / 6|Heat Treating
KT-300D300 / 51015 / 11|Coating
KT-500D500 / 85030 / 22|Transformer Drying
KT-850D778 / 132240 / 30|Metallurgy

KC and KTC Two-Stage Rotary Piston Pumps

  • Recommended for applications where operating pressure is below 0.1 Torr (0.13 mbar)
  • Achieve lowest possible pressures from mechanical pumps
  • No metal-to-metal contact between pump piston & cylinder – clearances are filled with oil
  • Unequaled durability, even in dirty applications

KC & KTC pumps are air-cooled. KTC-112 is water-cooled with optional air-cooling systems. Adjustable gas ballast valves are standard for handling water and other vapor loads. KTC pumps feature triplex piston design: dynamically balanced and practically vibration free.

ModelCFM / m3/hHP / kW|Typical Applications
KC-55 / 8.50.33 / 0.25|Evacuating Refrigeration Systems
Model CFM / m3/h HP / kW
KC-5 5 / 8.5 0.33 / 0.25
8 / 13.60.75 / 0.56|Liquid Gas Storage
KC-1515 / 25.51 / 0.75|Brake Fluid Filling
KTC-2121 / 361.5 / 1.1|Silicon Crystal Growing
KTC-6060 / 1023 / 2.2|
KTC-112107 / 1827.5 / 5.6|

KD and KDH Single-Stage Duplex Rotary Piston Pumps

  • Absolute pressures down to the low micron range
  • Belt-driven, low-speed rotary piston pumps
  • No small orifices to plug up
  • No metal-to-metal contact between pump piston and cylinder – clearances are filled with oil
  • Adjustable gas ballast permits handling of condensible vapors

KD pumps are air-cooled. KDH pumps are water-cooled.

ModelCFM / m3/hHP / kW|Typical Applications
KD-3033 / 561.5 / 1.11|Drying Chambers
KD-5052 / 882 / 1.5|De-gasifiers
KDH-130134 / 2275 / 3.7|Filling Machinery
KDH-150165 / 2807.5 / 5.6|Evacuation of Process

Liquid Ring Vacuum Pumps

Customers can choose a custom or optimized liquid ring vacuum pump from Tuthill and install with confidence it will do the job! Lean on our excellent service, support and engineering expertise.

KLRC Two-Stage

  • Can pull down as low as 4 Torr (5.3 mbar a)
  • Low-pressure performance is limited by the vapor pressure of the sealing liquid: water, oil or process liquids
  • Complete engineered system solutions available: instrumentation, controls, piping and valves
  • Self-contained liquid recovery and recirculation are available
  • Center-anchored tie rods allow access to either end of the pump without total disassembly
  • Double mechanical seals available in models KLRC75 through KLRC525 to meet API Piping Plan Requirements

Available in standard, all iron construction (no yellow metals) and 316 stainless steel. Liquid ring pumps often require water-cooling, but air-cooling systems are available.

ModelCFM / m3/hHP / kW|Typical Applications
KLRC-7570 / 1205 / 3.7|Vapor Recovery
KLRC-100100 / 1707.5 / 5.5|Deaeration
KLRC-125140/ 24010 / 7.5|Extruders
KLRC-200200 / 34015 / 11|Crystallizers
KLRC-300300 / 51025 / 18.5|Chemical Processing
KLRC-525550 / 93550 / 37|
KLRC-950950 / 1615100 / 75|

A Series Single-Stage

  • Simplistic in design, rugged in construction – handles even slugs of liquid
  • Unique axial flow design allows pump to operate flooded without damage
  • Built to run in the most severe of industrial conditions
  • Flat power curve over entire vacuum range prevents motor overload
  • No contact between operating components in the casing
  • Pull down to 29” Hg – 25 Torr (33 mbar a)
  • Increased water handling capability prevents heat build-up, extends life of single mechanical seal
  • Reduced stress on motor shaft and bearings
  • Compact, close-coupled design eliminates need for interstage manifold or motor alignment

A Series pumps are not as susceptible to cavitation compared to flat plate design because the flow path through the pump is an axial flow. This allows the velocity through the pump to be unchanged and carries the air out effortlessly. It is not unusual for these pumps to run 24/7 operation for years without maintenance.
Material of construction options include all bronze, cast iron, and stainless steel..

ModelCFM / m3/hHP / kW|Typical Applications
A-510 / 171 / 0.75|Gas Compression
A-1015 / 261.5 / 1.1|Sterilization
A-1522 / 372 / 1.5|Solvent Distillation
A-2035 / 593 / 2.2|Degasifiers
A-7575 / 1285 / 3.7|Extruders
A-100105 / 1787.5 / 5.5|Evaporators
A-130140 / 23810 / 7.5|
A-200220 / 37415 / 11|
A-300300 / 51020 / 15|

Rotary Vane Vacuum Pumps

The KVA’s simple design ensures the reliability and the durability that is required in the vacuum industry. Customers choose Tuthill for competitive pricing, local distribution and service, and superior customer service. Engineered-to-order system designs available.

KVA Single Stage

  • Most models can achieve ultimate pressure levels near 0.1 mbar (75 microns)
  • Ideally suited for clean or moderately contaminated applications when suction filters are fitted to the pump
  • Compact design for easy installation
  • Carbon composite vane material for long life
  • Oil-flooded, multi-vane vacuum pumps are single stage, air cooled and direct driven
  • Oil level sight glass and vibration isolators
  • TEFC high efficiency tri-voltage motor (208-230/460V 50/60)
  • Models KVA 25-630 include spin-on oil filter and exhaust pressure gauge
ModelCFM / m3/hHP / kW|Typical Applications
KVA-127 / 12.75 / 0.55|Vacuum Packaging
KVA-2115 / 261.0 / 0.75|Plastic Thermoforming
KVA-2521 / 362.0 / 1.5|Food Processing
KVA-4028 / 482.0 / 1.5|Central Vacuum Systems
KVA-6345 / 783.0 / 2.2|
KVA-10071 / 1205.0 / 3.7|
KVA-160124 / 2107.5 / 5.5|
KVA-250177 / 30010 / 7.5|
KVA-400300 / 50515 / 11
KVA-630460 / 78025 / 18.5|

Vacuum Boosters

Vacuum boosters are used to supercharge vacuum pumps to extend pump performance. This creates much faster pumping speeds and deeper vacuum levels. Tuthill’s vacuum boosters are designed to handle the world’s toughest applications.

  • High-capacity gas volumes at high vacuum (50 Torr to micron range)
  • May be used in conjunction with all types of vacuum pumps
  • Designed to operate at 82 dB(A) or less at blank-off (open field; motor and background noise excluded)
  • Supplied with a heavy-duty drive shaft for either direct coupled or belt-driven applications
  • Standard construction materials: cast iron housing, end plates and port fitting with ductile iron rotors and shafts
  • Special materials offered: stainless steel, carbon steel, ductile iron, Bi-Protec
  • Special testing available: Hydrostatic testing to 150 PSIG (10.35 bar g), seal leakage testing, noise testing
ModelCFM / m3/h|ModelCFM / m3/h|Typical Applications
15050-150 / 85- 255|2200860-2300 / 1461-3908|Supercharging Vacuum Systems
24070-230 / 119-391|29001130-3000 / 1920-5097|Vacuum Drying
400120-400 / 204-680|36001400-3600 / 2379-6116|Dehydration
540170-540 / 289-918|45001730-4500 / 2939-7646|Packaging
720230-720 / 391-1223|3200800-3200 / 1359-5437|Distillation
8500-850 / 459-1444|42001000-4200 / 1699-7136|Vacuum Furnace
1200400-1240 / 680-2107|54001400-5700 / 2379-9684|
1600500-1600 / 850-2718|73001800-7400 / 3058-12573|
2000650-2000 / 1104-33984000890-4000 / 1512-6796
2700850-2700 / 1444-458765001400-6400 / 2379-10874
1800680-1800 / 1155-3058|79001800-8000 / 3058-13592|
80002100-9500 / 3568-16141
100002800-10000 / 4757-16990

Dry Screw Vacuum Pumps

Dry screw vacuum pumps are environmentally friendly as there is less oil to dispose of and maintain within their design. These pumps are more efficient than a liquid sealed model and are well suited for industrial and process applications.

KDP Screw-Type Dry Vacuum Pump

  • Simple, robust design can handle process by-products – liquids, condensate, and even small particles
  • No oil or water in contact with process
  • No contact between operating components in the casing
  • Full pumping speed from atmospheric pressure down to 1 Torr; ultimate pressure 0.1 Torr (.05 Torr on Model KDP-800)
  • Quiet operation – less than 85 dB(A)
  • Short gas path through the pump for quick discharge
  • Extended shaft for either V-belt or direct drive
  • Casing and rotors made of ductile iron, PFA coated
60 Hz, Direct Drive
CFM / m3/hHP / kW|50 Hz, Direct Drive
CFM / m3/hHP / kW|Typical Applications
KDP-15088 / 1807.5 / 5.5|KDP-15071 / 1207.5 / 5.5|Solvent Recovery
KDP-330194 / 33015 / 11|KDP-330159 / 27015 / 11|Vapor Recovery
KDP-400235 / 40020 / 15|KDP-400194 / 33020 / 15|Vacuum Coating
KDP-800459 / 78030 / 22|KDP-800388 / 66030 / 22|Freeze Drying


Pump Testing

It shows that our client/customer base is becoming more sophisticated; because we see an increase in requests for performance tests. Testing is a great opportunity for us to exhibit our integrity and professionalism when our pumps are subsequently proven to meet the published performance data.

If the customer requires pump performance testing, the specific pump test and consequently the acceptable tolerances must be defined. The industry standard specification for our pumps is ANSI/Hydraulic institute 14.6-2011. But note, even within that 75 page specification there are numerous variables, detailed options and tolerance classes that remain to be defined.

The time to have the test, the delivery schedule and the subsequent costs defined is before the order is placed.

-Jim Elsey


Pumps are not “Plug and Play”

I repeat this message annually… no, monthly. No matter the manufacturer; the majority of all pumps do NOT come from the factory ready to start up.

The pump will require oil to be added to the bearing housings.

The impeller clearance must be determined and set for the fluid temperature. The direction of rotation should be ascertained and matched to the phase rotation on the motor driver (you must do this step with the coupling removed).

The driver will need to be aligned to the pump. When I tell people that they should align their pump nine times, I get some funny looks, but allow me to explain. Yes, the alignment may have been performed in the factory, but the very second the unit was moved for transport the alignment was lost. You will need to recheck the alignment when the unit is installed and leveled, again when the base is grouted, again after the piping is installed and again after the pump has been running up to temp.

The mechanical seal will need to be set after the above steps are completed.

Finally… please understand that most manufacturers do not install the coupling at the factory because it will just need to be removed for all the above reasons.

Be ready to complete these items, so you look like a pump professional.


-Jim Elsey


Pumps Have Boundaries

Pressure and temperature boundaries are the most common violations we see in this boundary category. Don’t forget that pump suction pressure is part of the overall discharge pressure calculation.

Note: Allowable pressure limits decrease with increasing temperature and not all materials have the same ratings.

If there is any doubt please consult with us. We can send you a rating chart for both 150 and 300 class flange ratings.
Do not get a ticket from the boundary police.

-Jim Elsey


Vapor Pressure is NOT Your Friend

Be very careful on self-primer lift applications because the liquid temperature
directly affects its vapor pressure and that…

changes the Net Positive Suction Head Available (NPSHA).

Example: Self-Primer – two temperatures… two outcomes:
For the example we will use two versions of the otherwise same application. The applications are identical in both versions except the temperature of the fluid is higher in the second version. The higher temperature signifies the vapor pressure has increased.

*Note: 14.7 PSI absolute atmospheric pressure x 2.31 divided by the Specific Gravity of 1 = 33.96 feet ≈ 34).
Any increase in elevation will reduce your absolute pressure (head) and consequently the NPSHA.

In Example A the fluid is water at 68ºF.
In Example B the fluid is water at 150ºF
As you look up the vapor pressure of water for each temperature note it is normally expressed in PSIA (pounds per square inch absolute) and so you need to convert that value to feet (head) then you will have the component value in the proper units needed to do the NPSHA calculation. Remember that to convert PSI (or PSIA) to head, you must multiply by 2.31 and divide by the specific gravity.

You can find these vapor pressure and specific gravity values in several places;
I use the Cameron Hydraulic Data Book or Cranes Technical Publication 410
(There are also several reputable web based sources).

Once you have the conversions then fill in the values for the formula and do the simple math steps (0.33889 X 2.31 = 0.783 ft. and 0.783 divided by 1 is 0.783). Then fill in the values in the NPSHA formula and complete the steps for the answer. Repeat these steps using the different values for Example B.

Note: The difference between the two versions for the value of NPSHA = 7.98 feet which is approximately 8 feet.

Summary: With all the parameters except temperature (vapor pressure) the same and simply changing the temperature of the fluid from 68 to 150 degrees we reduced the NPSHA by 8 feet. This may not seem like a big deal until you realize that the pump requires 13 feet of NPSHR at the condition point and now 12.24 feet is all that is available. The pump will not operate correctly and will be in a constant state of cavitation.
Corollary: Most pump manufacturers do not recommend using self–primer pumps on lift applications above 145°F for this reason. The solution for fluid temperatures above 145ºF will likely involve a vertical sump pump or a submersible pump.

-Jim Elsey