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Product code: R Wobble

North Ridge R Wobble Progressive Cavity Pump

Pump Type - Progressing Cavity

Max Flow Rate M³H - 6 M³H

Max Head - 60M

Pump Materials - AISI304, AISI316, Cast Iron

Max Temp - 80°C

Max Viscosity - 5000 cst

Max Solid Passage - 5mm

Self Priming - Y

Inlet/Outlet Sizes - 24mm to 88mm

Drive - AC Electric, Bareshaft

Max Suction Lift - 4M

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£730.80 (inc VAT) £609.00 (ex VAT)

This product has a delivery lead time of 3-4 Weeks

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DESCRIPTION

North Ridge R Wobble Progressive Cavity Pump

Flow Rate	Up to 6m³/hr
Head (Pressure)	Up to 6 bar
Sizes Available	From R24 to R88
Operating Temperature	-40°C to 80°C
Drive Options	Electric Motor

The North Ridge R series progressive cavity pump is commonly known as a Wobble pump. It is extremely small and compact but still has all the benefits of a normal progressive cavity pump. It has excellent self-priming capability, can handle viscous fluids, slightly abrasive fluids and fluids containing solids in suspension. This small helical rotor pump produces very few vibrations and has a non-pulsating flow making it excellent at handling shear sensitive fluids. Despite its compact design, it is still capable of achieving flow rates up to 6m³/hr and pressures up to 6 bar.

The casing of this positive displacement pump can be constructed from various materials including cast iron, stainless steel 304, stainless steel 316 and bronze. The rotor is available in stainless steel 304 and 316, while the stator can be supplied in NBR, EPDM and FPM.

There are no dead zones within the pump making it suitable for use in food and beverage applications such as wine, beer and vegetable oil transfer. The stators are also available food grade certified.

The wobble pump series is mechanically sealed as standard.

This small progressive cavity pump is ideal for many applications in the industrial and marine markets, including; fuel transfer, oil transfer, sewage transfer, polymers, flocculants, oily sludge, bilge water transfer, waste water transfer, sludge transfer, marine and agriculture.

Product summary

• Close coupled compact design

• Easy to maintain due to small number of parts

• Available in cast iron, bronze and stainless steel

• Mechanical seal

• Excellent self-priming capability

• Excellent at pumping fluids containing solids in suspension

• Excellent for shear sensitive fluids due to low pulsations

• Single phase and three phase 50hz / 60hz motors

• Marine certification available

• Various accessories available, including; bypass valve, flow switch, pressure switch, control panel and inverter.

Read how Progressing Cavity Pumps work and the types available in our Guide

FAQS

Can this pump run dry?

No, definitely not! Progressive pumps will incur damage even after short periods of dry running. Firstly, the stator and rotor require lubrication from the pumped fluid. Dry running without these will cause fast and irreversible damage. The mechanical seal requires lubrication and cooling while the pump is operating. Without the presence of fluid, the mechanical seal will overheat and crack, and this may cause the pump to leak and fluid to enter the motor. There is also the possibility that the motor will burn out. Our advice is to ensure that the pump always has access to fluid while running, the vessel or sump on the inlet side of the pump must never run out of fluid while the pump is active. Level sensors or a float switch can be installed in the fluid chamber ensuring that the pump is turned off in the event there is no fluid. Another way of protecting the pump is to fit a dry running device, this will turn the pump off if it detects that no fluid is entering the pump. If you think that dry running is inevitable, then please speak to us and we will try to select a more suitable pump for your application.

What does the term self-priming mean?

A pump must be primed in order to operate correctly, this means that the pump casing and inlet pipe must be filled with fluid and the air removed before operation. This needs to be done manually by the pump operator for a non-self-priming pump each time the pump is used to avoid damage from dry running. A self-priming pump removes these issues by completing the priming process automatically. The air is removed from the inlet pipework and pump casing when the pump is activated. Self-priming pumps are particularly useful for installations with a suction lift on the inlet side of the pump, the pump will draw the fluid up the pipework by creating a vacuum and removing any air that is present. In ideal conditions, a self-priming pump can lift fluids up to around 8m on the inlet side, however this figure is affected by fluid viscosity, pipework bore and other installation conditions, therefore this figure can be much lower from case to case. Allowances must also be made for wear and tear; suction lift capabilities will be much lower for older and worn pumps.

What viscosity can this pump handle?

Please be aware that the figures displayed relate to the largest pump from this range of products, not specific models. For details on viscosity for specific models, please refer to datasheets or contact a member of our sales team.

What size solids and percentage dry matter can this pump handle?

Please be aware that the figures displayed relate to the largest pump from this range of products, not specific models. For details on solids passage and dry matter content for specific models, please refer to datasheets or contact a member of our sales team.

What is a hopper and do I need one?

A hopper is a wide opening at the top of the pump, it is designed to help feed viscous, sticky, dry, pasty and solids laden fluids into the pump easier than just via standard pipework. Our hoppers are customisable; they can be manufactured to various shapes and sizes, they can also be fitted with various types of feeding systems, including auger screw and paddle.

How do I know what size pump and motor speed is correct for my application?

A clear picture of the pump system is required to make an accurate selection. The main pieces of information required include; a description of the application, bore of pipework, the fluid, viscosity, size and type of solids, flow rate and pressure/head. With these pieces of information, a pump can be sized correctly to ensure it delivers the required flow rate and pressure and that is also operates at its best efficiency point to lower lifetime costs. Knowing if the pump is running intermittently or continuously also allows the correct motor speed to be selected. For instance, a pump running continuously 24/7 will require a slower speed motor rather than a full speed motor. Running the motor slower and oversizing the pump will reduce wear of the motor and the pump, therefore lowering maintenance costs during their lifetime.

How do I know what pump materials are correct for my application?

Firstly, always check the compatibility of the materials available against the fluid being pumped. The main materials to check are the pump casing, stator, rotor, o-ring and mechanical seal. It may be that more than one material is suitable for your fluid and selection could be based on the application type. If it is a simple transfer application with a clean fluid, then the most cost-effective material will be best. However, if it involves more complex variables such as high temperature and abrasive solids then other materials will need to be considered.

How does a bypass work and do I need one?

An integral bypass is designed to protect the pump and system from overpressure for small periods of time. It is typically set to around 10% higher than the working pressure, it will open and recirculate the fluid inside the pump head when the set pressure is achieved. An integral bypass is only a temporary solution and cannot operate indefinitely, an additional external bypass that runs back to the fluid source is always recommended as a more permanent solution.

What do the terms Atex and explosion proof mean and why are they so important?

ATEX is an abbreviation of “Atmospheres Explosibles”. It is a regulation set out by the European Union to ensure the safety of products that are used to handle flammable products or are installed in environments containing flammable gases, vapours, mists or combustible dusts. For instance, if the pump is being installed in an explosive environment, then only the motor needs to meet the Atex standard stopping it from causing a spark during operation and igniting the atmosphere. However, if the fluid being pumped is flammable, then the pump will also need to meet Atex standards to ensure that no sparks are caused inside the pump itself when the fluid goes through it. It is crucial that an Atex rated pump or motor are used for applications involving explosive environments or flammable fluids, using a non-Atex pump or motor in these situations is extremely dangerous and contravenes health and safety standards.

What is NPSH and why is it so important?

NPSH is an acronym for Net Positive Suction Head. NPSH measures the absolute pressure present in a fluid.

There are two main ways that NPSH is expressed in a pump system

NPSHa - This is the amount of Net Positive Suction Head available at the pump inlet. NPSHa demonstrates the amount of pressure acting on a fluid as it enters the pump. This measures the amount of pressure between the liquid staying in its current state and forming vapour bubbles (beginning to boil).

NPSHr - This is the amount of Net Positive Suction Head that the pump requires to operate without experiencing the damaging effect of cavitation, thus causing a dramatic reduction in pump performance.

It is very important to pay attention to these values when making a pump selection. Selecting a pump that requires more NPSH than is available in your system will cause fast and long-lasting damage to the pump and thus you will incur large repair costs and downtime.

What is a Wobble Pump?

Wobble pumps are very similar in working principle to Progressing cavity Pumps, but with slight differences in design.

They are more compact, smaller in length and often utilised for lower flows and pressures. They cover around 3% of the flow of normal progressing cavity pumps.

Being directly coupled to motors and assembled without a gearbox, reduces their overall length making them compact and space saving in design. This means the pump runs at full motor speed where as on typical PC pumps, the speed is reduced via a gearbox to accommodate more viscous and abrasive fluids.

Why are they called Wobble Pumps?

The internal working mechanism contains a single joint as opposed to two, causing the stator to wobble, where as in a typical progressing cavity pump the stator is fixed and only the rotor rotates in a smooth 360° motion.

How does a wobble pump Work?

A wobble pump works by a motor driving the pump shaft which in turn causes the rotor to wobble. Normally in Progressive cavity design the rotor will perform a full 360° rotation, whereas in this design the rotor wobbles hence its name.