Mechanical diaphragm

GM / GB series

Mechanical diaphragm metering pump, up to 1,800 L/h at up to 12 bar

GM / GB series: mechanical diaphragm metering pumps for accurate, repeatable dosing of chemicals and additives. 24 models from 2.25 to 1800 L/h, with pressure up to 12 bar. Pump-head and diaphragm materials are chosen for your liquid; send us the chemical, concentration and temperature and we will confirm the right head.

Variable eccentric structure: smooth flow pulsation; wear-resistant ball bearings; oil-bath lubricated drive
Flow adjustment when stopped or running: manual, electric or frequency conversion
Mechanical drive diaphragm; material side without diaphragm; self-cleaning check valves
Pump heads in PVC, PVDF, 316SS, and high-viscosity / slurry versions
Options: double diaphragm head, diaphragm rupture detection with gauge and pressure switch, stroke counting sensor, PNP/NPN or relay output
Electric stroke controller: 4–20 mA input (single-phase 220 V 50 Hz); three-phase motor with on/off control or 4–20 mA / pulse control (200–240 V, 50/60 Hz)

View 24 models

Flow: 2.3–1800 L/h
Pressure: up to 12 bar
Models: 24

Sizes

The 24 models of the GM / GB series range grouped by type. Open the Models tab for every model with its performance data.

Type	Flow range	Pressure	Motor	Models
GB	82–1800 L/h	3–10 bar	550–750 W	12
GM	2.3–500 L/h	5–12 bar	250–370 W	12

Models

Filter by duty point, mains frequency or size. Click a model for its performance curve and data.

Model table (PDF)

Model	Series	Flow L/h	Pressure bar	Strokes/min	Motor W	Plunger mm
GM0002	GM	2.3	12	36	250	—	Details
GM0005	GM	4.5	12	36	250	—	Details
GM0010	GM	9	12	36	250	—	Details
GM0025	GM	25	12	72	250	—	Details
GM0050	GM	50	10	144	250	—	Details
GM0090	GM	85	7	72	250	—	Details
GM0120	GM	115	7	72	250	—	Details
GM0170	GM	170	7	144	250	—	Details
GM0240	GM	235	7	144	250	—	Details
GM0330	GM	315	5	144	250	—	Details
GM0400	GM	400	5	144	370	—	Details
GM0500	GM	500	5	180	370	—	Details
GB0080	GB	82	10	36	550	—	Details
GB0180	GB	167	10	72	550	—	Details
GB0250	GB	237	10	102	550	—	Details
GB0350	GB	334	10	144	550	—	Details
GB0450	GB	416	10	180	550	—	Details
GB0500	GB	464	7	144	550	—	Details
GB0600	GB	583	7	180	550	—	Details
GB0700	GB	656	3.5	102	550	—	Details
GB1000	GB	946	3.5	144	550	—	Details
GB1200	GB	1200	3.5	180	750	—	Details
GB1500	GB	1500	3	180	750	—	Details
GB1800	GB	1800	3	206	750	—	Details

Performance range

Every model of the GM / GB series range by flow and pressure. Click a line or dot to open that model with its full data.

Logarithmic scales. Published catalogue data for clean water; the correct model for your duty is confirmed by our engineers.

Spare parts for GM / GB series

Typical wear and service parts for this type of pump. The exact part, material and part number depend on the model, so send us the model code (or a nameplate photo) and we confirm and quote the right one.

Request spare parts quote

Part	What it does
Diaphragm	The flexing membrane that moves the liquid; replaced at the service interval
Check valves (suction and discharge)	Valve balls, seats and springs that give one-way flow
Pump head	Liquid end in the material suited to the chemical
Gaskets and O-rings	Seal the head, valves and connections
Hydraulic oil and relief / bleed valve	Hydraulic diaphragm types only: transmits the stroke and protects against over-pressure
Stroke adjuster and motor	Sets the flow rate and drives the pump

Generic list for this pump type; it is not a part-number catalogue for the series. Our team confirms the correct part for your model before quoting.

Specification & options

Key parameters

Max flow rate1800 L/h
Max pressure12 bar
Accuracy±1 % of rated flow (30–100 % of flow range)
Max suction lift3 m water column
Max inlet pressure2 bar
Max ambient+40 °C

Fluid end and materials

Fluid end	Valve body	Valve seat	Valve ball	Diaphragm	Seal ring
PVC	PVC	PVDF	Zirconia	PTFE	FPM/EPDM/Fluororubber
PVDF	PVDF	PVDF	Zirconia	PTFE	FPM/EPDM/Fluororubber
316SS	316SS	316SS	316SS	PTFE	FPM/EPDM/Fluororubber

Technical data

Typical applications

Environmental protection
petrochemical
chemical
oil refining
electricity
metallurgy
medicine
food

Data basis

CNP metering pump selection manual, printed pp. 15–18

Performance values are taken from the published CNP catalogue data. Our engineers confirm the final selection for your liquid, temperature, supply and site before quoting.