Why Side Channel SIHI Pump?                                                      

The Sterling SIHI CEH pump is a self-priming side channel pump capable of handling gas along with the medium and operates at a low noise level. The CEH pumps are used for problem-free pumping of clean liquids at unfavourable suction side conditions. They are also very suitable for positive suction heads below 0.5m

The different material possibilities with uniform dimensions and performance characteristics as well as the standard exchangeable components, make the CEH particularly recommendable for applications in the pharmaceutical, chemical or petrochemical market as well as in the plastic or oil industry.

Because of its low NPSH and positive suction head the CEH is very suitable for the pumping of liquefied gasses and liquids under vapour pressure like condensate, refrigerant, boiler feed water or LPG. The pumps of the CEH /7 series have a retaining stage to avoid the dry running by controlling the liquid level in the pump.

This design is especially developed for the handling of liquids under vapour pressure or when pumping from underground tanks. The series CEH /5 are used for bottom off-loading of liquids under vapour pressure.

Shaft Sealing                              

The shaft can be sealed by a stuffing box or a mechanical seal conform DIN EN 12756. The shaft sealing is also available in a design suitable for heating or cooling of the stuffing box or the mechanical seal.

Double mechanical seal (back-to-back as well as tandem) or a quench design with throttle bush are available upon request. The CEH can also be supplied with a magnetic coupling.

Flanges                                                       

The flanges correspond to DIN EN 1092-2 / PN 40. Flange design as per DIN 2512 with groove or drilled according to ANSI 150 or 300 lbs is basically possible.

Casing Pressures                                                       

Maximum 40 bar from -40 °C up to +120 °C

Maximum 32 bar from +120 °C up to +180 °C

Pressure stages for temperature as per DIN EN 1333

Design                                                       

Pumps of the series CEH have a segmental type construction with open vane wheel impellers. The construction of the CEH pump is a so-called centrifugal combined system. This combination pump is suited with a centrifugal stage in serial connection before the side channel stages to obtain a more favourable NPSH.

The program comprises 6 sizes each with 1-8 stages. The existing material design allows an optimum rating for the respectively desired performance range and the pumping medium. Pumps of the series CEH /7 are equal to the CEH series but equipped with a retaining stage.

This program comprises 6 sizes with 2-7 stages. The series CEH /5 have also 6 sizes but with 2-8 stages. The applied hydraulic components are from our Modular Side Channel system (interchangeability of parts).

Operating Principle                                                       

The CEH pump or so-called centrifugal combined system (combination pump) is suited with a low NPSH centrifugal impeller before the side channel stages (series connection). This NPSH inducer stage creates enough pressure to overcome the entrance pressure loss of the first side channel stage or NPSH required.

A side channel stage consist of:

• a suction intermediate piece with the suction port,

• a discharge intermediate piece with the side channel, the air displacement channel at the end of the side  channel, the discharge port and the gas slot,

• a vane wheel impeller enclosed by the two intermediate pieces.

The turning of the vane wheel impeller creates an under pressure at the beginning of the side channel (centrifugal effect) and the gas or liquid with gas is drawn in. The air displacement channel provokes a positive displacement effect so the gas remaining at the root of the vane wheel impeller is forced out through the gas slot. The pressure generating is obtained by the repetitive re-entering of the liquid in the side channel (corkscrew movement).

A side channel pump can de-aerate and degas the suction line by itself and is thus very suitable for suction lift operation. A side channel pump can handle large quantities of (entrained) gas. Mixtures up to a gas share of 50% are possible. The ability for selfpriming and the handling of large amounts of (entrained) gas, will guarantee continuous operation even in case of evaporation and therefore contribute to a higher level of safety in industrial processes.

To avoid cavitation the distance between the liquid level and the entrance at the suction side of the pump is restricted. This distance is related to the NPSH or Net Positive Suction Head. The NPSH for CEH pumps is very low due to it special construction. The axial entrance and its larger diameter results in a less disturbed flow and lower friction losses. Together with the low NPSH of the centrifugal impeller the CEH can handle a positive suction head of less than 0.5 m. This makes the CEH very suitable for pumping liquids near their boiling point at reasonable economic expenses and the low NPSH guarantees also full output capacity because of operation without cavitation.

Low NPSH Capabilities                                                       

General conditions

Liquid: Water

Density: 1kg/dm³

Viscosity:1 cSt

Temperature: 20°C

Atmospheric pressure: 1013 mbar

Characteristic tolerances

Capacity ± 5% - Delivery head ± 5% - Power + 10%

For designs with a mechanical seal or a casing seal of soft Teflon, the tolerance for the delivery head is extended by 2% each.

Measuring standard

According to ISO 5198

The NPSH curve is suitable for liquids without gas. When using a liquid containing gas (e.g. water 20 °C) a safety margin of 1 m has to be added.

Applications                                                       

Sterling Fluid Systems offers an extensive Side Channel pump range under its brand name Sterling SIHI. Sterling Fluid Systems has more than 80 years of experience in manufacturing, installation and support of Side Channel pumps. The Sterling SIHI Side Channel pumps can be found in a wide application range for the:

• Self priming

• Gas handling

• High-resistant materials

• Performance curve characteristics

• High efficiency

• Low NPSHR value

• Modular hydraulic system

• Chemical market

• Pharmaceutical industry

• Petrochemical industry

• Food industry

• Ship yards

• LPG industry

• and many more ...

The Sterling SIHI Channel pump range

The benefits of the Sterling SIHI Side Channel pumps

• Self priming

• Gas handling

• High-resistant materials

• Performance curve characteristics

• High efficiency

• Low NPSHR value

• Modular hydraulic system

Video