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pressure testing pump
General Information for Air driven liquid pumps
USUN air driven liquid pumps are ratio devices that utilize low pressure compressed
air driving a larger diameter piston (area x pressure) which is linearly connected to a smaller
hydraulic piston/plunger. Using this ratio principal, a higher hydraulic pressure can be generated.
Usun Pump model numbers reflect the pumps nominal pressure ratio, while the technical data
indicates exact ratios. The outlet stall pressure is easy to set by adjusting the air drive pressure
through a simple air pressure regulator.
By multiplying the pressure ratio by the available shop
air pressure, the nominal liquid pressure can be calculated.
Exmple ( Pump Model: AT644 liquid pump)
Air drive piston area ( 160mm Ø)
Hydraulic plunger area ( 20 mm Ø)
Actual ratio = 64:1
1. AIR DRIVE SECTION
The air drive section consists of a light weight piston complete with seals running inside an
aluminum barrel. The diameter of the air piston is 80mm. When compressed air is supplied to
the pump the air pushes the air piston down on a compression stroke
( forces fluid out of the liquid end).
Under the control of pilot pins (poppet valve) triggered at each end of the stroke
2. HYDRAULIC SECTION (Wetted End)
The hydraulic section of an air driven liquid pump consists of 4 main pieces, the hydraulic body,
the piston/plunger, the check valves and the main high pressure seal. The hydraulic
piston/plunger is directly linked to the air piston and it is housed inside the hydraulic body and
its movement up and down creates the liquid flow into and out of the pump through the check
valves. The check valves are spring loaded and on the suction stroke the inlet check valve
opens to the maximum allowing fluid into the hydraulic body and on the compression stroke the
inlet check valve closes and the discharge check valve opens forcing the pumped fluid into the
process. The main high pressure seal is located within the hydraulic body and the piston/plunger seals
against this during operation. There are different materials and designs of high pressure seals
Typical applications for pneumatic driven water testing pump 
Key features
One model available in 8 ratios
Compatibility with a variety of liquids
Safe pneumatic operation
Aluminum bodies and wetted materials of carbon steel or stainless steel
Rugged,compact,reliable and easy maintenance proven design
High quality seals, long service life available
No need for air line lubrication
Wide application with large range of pressure ratio
Main technical data 
Typical technical data for pneumatic driven water pump
| AT Serial Air liquid pump | |||||||||||||||||||||
| Technical data Base on air driven at 7Bar , air consumption is around 0.9M3 per min | |||||||||||||||||||||
| Base on air driven pressure at 7Bar | |||||||||||||||||||||
| Model | Piston/Rod diameter ø(mm) | Displacement per stroke (mL) | Liquid IN | Liquid OUT | Maximum outlet pressyre Bar@at 8.3Bar | Liquid Outlet pressure (Bar) 1Bar=0.1Mpa=1.019Kg/cm² | |||||||||||||||
| 0 | 20 | 40 | 70 | 100 | 150 | 200 | 300 | 400 | 500 | 600 | 700 | 900 | 1200 | 1700 | 2350 | ||||||
| Flow rate L/min (L/min) | |||||||||||||||||||||
| AT10 | 50 | 294.52 | NPT3/4'' | NPT3/4" | 83 | 35.34 | 26.51 | 20.62 | 17.67 | 11.78 | |||||||||||
| AT16 | 40 | 188.5 | NPT3/4" | NPT3/4" | 132.8 | 22.62 | 16.97 | 13.2 | 11.31 | 7.54 | |||||||||||
| AT20 | 35 | 144.32 | NPT3/4" | NPT3/4" | 166 | 17.32 | 14.43 | 12.99 | 11.55 | 10.1 | 0 | ||||||||||
| AT28 | 30 | 106.03 | NPT1/2" | NPT1/2" | 232.4 | 12.72 | 10.6 | 9.54 | 8.48 | 7.42 | 6.36 | 0 | |||||||||
| AT40 | 25 | 73.63 | NPT1/2" | NPT1/2" | 332 | 8.84 | 7.36 | 6.63 | 5.89 | 5.15 | 4.42 | 3.68 | 0 | ||||||||
| AT64 | 20 | 47.12 | NPT3/8" | NPT3/8" | 498 | 5.65 | 4.71 | 4.24 | 3.77 | 3.3 | 2.83 | 2.36 | 1.88 | 1.41 | |||||||
| AT80 | 18 | 38.17 | NPT3/8" | NPT3/8" | 664 | 4.58 | 3.82 | 3.44 | 3.05 | 2.67 | 2.29 | 1.91 | 1.53 | 1.34 | 1.15 | ||||||
| AT100 | 16 | 30.16 | NPT3/8" | NPT3/8" | 830 | 3.62 | 3.32 | 3.02 | 2.87 | 2.56 | 2.26 | 1.81 | 1.51 | 1.21 | 1.06 | 0.9 | 0 | ||||
| AT130 | 14 | 23.09 | NPT3/8" | NPT3/8" | 1079 | 2.77 | 2.66 | 2.54 | 2.31 | 2.08 | 1.85 | 1.62 | 1.39 | 1.15 | 0.92 | 0.81 | 0.69 | 0.23 | |||
| AT170 | 12 | 12.44 | NPT3/8" | NPT3/8" | 1411 | 1.49 | 1.43 | 1.37 | 1.31 | 1.24 | 1.12 | 1 | 0.87 | 0.75 | 0.62 | 0.5 | 0.44 | 0.37 | 0.12 | ||
| AT240 | 10 | 8.64 | NPT3/8" | *HF4 | 1992 | 1.04 | 0.99 | 0.95 | 0.91 | 0.86 | 0.78 | 0.69 | 0.6 | 0.52 | 0.43 | 0.35 | 0.3 | 0.26 | 0.22 | 0.17 | |
| AT300 | 9 | 7.32 | NPT1/4" | *HF4 | 2490 | 0.88 | 0.84 | 0.84 | 0.81 | 0.77 | 0.73 | 0.66 | 0.59 | 0.51 | 0.44 | 0.37 | 0.33 | 0.29 | 0.33 | 0.18 | |
| AT400 | 8 | 5.53 | NPT1/4" | *HF4 | 3320 | 0.66 | 0.64 | 0.64 | 0.61 | 0.58 | 0.55 | 0.5 | 0.44 | 0.39 | 0.33 | 0.28 | 0.25 | 0.22 | 0.21 | 0.19 | 0.14 |
Remark 1) Maxium outlet pressure are at an air driven pressure of 8 bar or 116 PSI ,for long life using
of such pump ,we suggest that air driven pressure should be not more than 8 Bar
Typical diagram of such air driven liquid pumps 
Product Applications 
