SEKO Spring PS1 Plunger Piston Dosing Pump 1.5-304 l/h

The SEKO Spring PS1 is a motor-driven plunger piston dosing pump for high-pressure, low to medium flow duties: 1.5 to 304 l/h at up to 20 bar (290 psi). Unlike the diaphragm MS1, it uses a stainless steel or ceramic plunger of 6 to 64 mm diameter with a 15 mm stroke, inside an aluminium housing with a spring return mechanism and an IP55 motor.

Heads are SS316L (dosing temperature up to 90 C) or PVC (up to 40 C), which makes the PS1 one of the few SEKO pumps in this series able to meter hot liquids.

Why choose a plunger pump over a diaphragm pump

A plunger pump compresses the liquid directly, so volume stays nearly constant against high back pressure. That is useful when dosing into boiler feedwater lines, pressurised reactors, high-pressure RO feed headers or long, restricted injection lines. With nine plunger diameters from 6 mm to 64 mm the PS1 can be sized from about 1.5 l/h at 6 mm and 58 strokes per minute up to 304 l/h at 64 mm and 116 strokes per minute, with maximum pressure falling as plunger diameter grows (20 bar to 6 bar for stainless steel heads).

Features listed in the datasheet

• Flow rates from 1.5 to 304 l/h; maximum pressure up to 20 bar (290 psi)
• Two stroke rates, 58 and 116 strokes/min; stroke length 15 mm
• Plunger diameters 6, 11, 17, 25, 30, 38, 48, 54 and 64 mm
• Motors 0.18 kW and 0.25 kW three-phase, 0.25 kW and 0.37 kW single-phase, IP55
• Stroke setting by hand or by an actuator accepting 4-20 mA
• Heads in SS316L (maximum dosing temperature 90 C) and PVC (40 C)
• Ambient dosing temperature +5 to +45 C; storage temperature -10 to +50 C

Technical specification and plunger table

* PVC models marked with an asterisk are available with a special reinforced head for pressure up to 20 bar (customisation code H).

Key code and how to order

The key code example P S1 D 011 C 31 A4 L 0 0 reads: P plunger piston, S1 piston mechanism, D stroke length 15 mm, 011 piston diameter 11 mm, C 116 strokes per minute (A is 58), head code 31 (PVC with ceramic piston and FPM seal), A4 motor 0.18 kW three-phase, L automatic linear actuator, customisation 0 and optional 0.

Head options: 21 SS316 with FPM, 24 SS316 piston ceramic with EPDM, 31 PVC ceramic with FPM and PTFE valve seat, 32 PVC with SS316 valves, 34 PVC with EPDM. Motors: A4 0.18 kW and B4 0.25 kW three-phase, H4 0.25 kW and I4 0.37 kW single-phase, AI and BI with inverter, S0 none. Customisation H gives the reinforced head for 20 bar on small plungers.

Installation and operation notes

Install with a calibrated relief valve on the discharge line, because a plunger pump produces whatever pressure the line demands up to its limit. Keep the suction line short and sized for the liquid viscosity, and check ceramic plunger and seals regularly on abrasive slurries. With hot liquids up to 90 C use the stainless steel head and confirm seal elastomer compatibility.

GCC applications

The PS1 is used for scale and corrosion inhibitor injection into boiler feed and cooling circuits, amine or oxygen scavenger dosing in steam systems, and metered injection of additives into pressurised pipelines. In Gulf climates liquid and ambient temperatures run high, so the 90 C stainless steel head and +45 C ambient limit are practical advantages.

Accessories and companions

Fit a relief valve, back-pressure valve, pulsation dampener, calibration column and strainer. The AKTUA linear actuator allows 4-20 mA stroke control. For lower-pressure larger-volume duty see the Spring MS1 and the Spring MSV; the full range is in Pumps.

Selection and installation notes

A dosing pump is sized from the flow and pressure at the injection point, so confirm the chemical, its concentration and temperature, the head and seal materials, the back pressure and the stroke or speed range before ordering. Fit an injection valve and a suction strainer, keep the suction line short, prime the pump before use, and use a pressure relief valve on the delivery side. Wear the protective equipment named on the chemical safety data sheet when servicing the pump.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Frequently asked questions

What is the maximum pressure of the PS1?
20 bar (290 psi). The limit falls with plunger diameter, down to 6 bar for the 64 mm plunger in SS316 and 4 bar in PVC.

Can it handle hot liquids?
The SS316L head is rated for a maximum dosing temperature of 90 C; the PVC head for 40 C.

How many stroke rates are offered?
Two: 58 and 116 strokes per minute at 50 Hz, with a fixed 15 mm stroke length.

Which motors are available?
0.18 and 0.25 kW three-phase, 0.25 and 0.37 kW single-phase, or inverter versions and a no-motor option.

How is flow adjusted?
By the stroke adjustment knob, or automatically with the AKTUA linear actuator on a 4-20 mA signal.

Documents and quotation

Our Muscat office quotes the SPRING PS1 as an independent supplier, with price, lead time and stock given per request. To start, share the flow in l/h, discharge pressure, liquid temperature, viscosity and motor supply. Please confirm plunger size, head code and motor code against your duty before ordering. The SEKO Spring PS1 technical data sheet rev 0.7 is attached to this product page if you want to compare figures.