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Gorman Rupp

What’s the maximum suction lift you can do?

The maximum practical suction lift is about 7.5m, but to achieve that the pump speed needs be sufficient for the re-prime lift (re-prime lift capability at the range of speeds is published on Gorman-Rupp Super T series and Ultra V series curves). NPSH is also another key consideration especially on the large suction lifts. We can advise on the max suction lift on your application, just contact us with the details.

Are surface mounted self primers reliable?

Absolutely yes ! provided they are correctly installed with particular attention to suction line configuration and provision made for air to be evacuated while the pump is priming the suction line.

Are surface mounted pumps noisy?

Noise varies as to the speed of the pump and where it is operating on the performance curve. A Gorman-Rupp Super T series pump operating in mid curve will typically be less than 70dBA at 1m with most of the noise coming from the standard foot mounted motor, towards top left of curve the noise increases on any pump. If your application is particularly sensitive to noise, run it by us and we will give you an honest expectation on the noise level

What size solids can you handle in Gorman-Rupp T series pumps?

We can handle up to 3” spherical solids on Gorman-Rupp T series pumps (from T4 through to T10), the T3 can handle 2.5” solids, the T2 1.5” solids. Solids handling is not all about free passageway, the Super T Series Eradicator system deals with rag build up as it enters the eye of the impeller (Click here for more information on the Eradicator system)

What are the advantages and disadvantages of vee belt drive?

Vee belt drive means the pump performance can be changed by the pulley ratio while using a full size impeller. If the pump is direct coupled rather than vee belt driven, an impeller trim or variable speed drive (inverter) is needed to vary performance. On our design of baseplates and motor stools there is also the added advantage of the rotating assemblies being removable via the motor stool cavity without disturbing the pump casing or motor.

You say the pumps are heavy duty and robust, how long do they last?

That depends on the application. On fairly light duties like a raw sewage pumping station it is not uncommon for a pump to last over 30 years, we have plenty out there in the field over that age. On highly abrasive applications like mud or grit pumping, obviously the lifespan of the pump is less but we can offer austempered ductile iron (hard iron) parts for those applications to extend the life as far as we can

What are the main health and safety benefits?

The pumps are surface mounted which means easy access for maintenance without using lifting gear or a involving a confined space entry (in the case of dry well pumps).

Are they easy to maintain?

Yes, incredibly easy since they are surface mounted with built in features such as external shimless adjustment, easy access fill and drain oil ports, removable back covers for inspection and easy replacement of key components such as suction check valves, impellers, and wear plates.

What is NPSH?

NPSH is Nett Positive Suction Head. For a pump to function correctly NPSH must be positive. A positive system is where after a vacuum has been formed and the pump is fully primed, there is enough atmospheric pressure available to push the liquid into the pump and through the pump at the required rate. As part of making a pump selection we do something called a NPSH calculation where we calculate NPSH available from the system by considering things like static suction lift, suction pipework losses, vapour pressure correction, altitude correction and atmospheric pressure safety factor. From that we subtract the NPSH required by the pump (which is published on the performance curves at the flow range). If that calculation is positive then the pump will perform as required, if its negative something has to change in the system or pump selection.

Why and under what circumstances do I need an air release valve?

An automatic air release valve provides an easy passage for air to be evacuated while the suction line is being primed. They need to be installed before a discharge non return valve. The discharge non return valve holds the pressure back while the air release valve does its job. Generally we say if the pump needs to develop air pressure of over 5m to lift a discharge non-return valve, then an automatic air release valve should be fitted.

Should an air release line outlet be open to atmosphere or be submerged in the sump?

In most cases the we recommend the air release line should be submerged approx. 150mm below low level cut out in the sump, that’s unless there is a large difference (say over 3m) between stop and start levels in the sump, or if the air release valve is being used to break a syphon (if static discharge head is negative, ie runs down hill). Submerging the air release line helps to retain prime in the suction pipework (in the event of the internal check valve failing to seat properly due to a small obstruction).

Can Gorman-Rupp Super T Series handle stringy material such as sanitary products, hair nets and feathers?

Yes, if the effluent contains those types of items, then we recommend the Gorman-Rupp Super T Series fitted with Eradicator system. Click here to find out some more information

What is the maximum primary sludge concentration a Gorman-Rupp T series pump can handle?

If the pump operates on a suction lift, then generally we say 4% is a good maximum guideline. If the pump operates on a flooded suction, then this can be pushed out to 5% -7% but we recommend on site trials since the sludge characteristics at each site can vary, its not all about % solids.

What is the best way to install a self priming centrigugal pump?

A few golden rules;

  • Keep the suction line as short and simple as possible.
  • Make sure you have individual suction lines.
  • Give consideration to the route air will be evacuated, use automatic air release valves at their correct setting in conjunction with discharge non-return valves. Submerge the air release line outlets 150mm below pump stop level.
What is the cost comparison of a Gorman-Rupp T series pump compared to a traditional submersible type sump pump?

Generally submersible pumps (either wet well or dry well) will be less initial cost than Gorman-Rupp T series. The better return on investment (ROI) on Gorman-Rupp pumps comes from the far longer asset lifecycle, reduced civil engineering costs, and reduced maintenance costs.

It’s a USA manufactured product, are replacement pumps and spare parts on long lead times?

No, we carry extensive stock at our Peterborough location which enables us to ship common replacement pumps and spares same day or next day. Gorman-Rupp also have a huge inventory of pumps at spares at their Netherlands and USA based warehouses which we expedite using very efficient International Freight companies.

What is the difference between wet prime and dry prime pumps?

Wet prime pumps need some liquid retained in the casing and use a recirculation method to prime. Gorman-Rupp pumps are designed to retain enough liquid in the casing to re-prime even if the internal suction check valve does not seat fully. They have advantages of dry prime in the fact they do not require any other equipment to prime.

Dry prime pumps use either a venturi or diaphragm device to prime the suction system. The pump is a traditional end suction centrifugal type. Dry prime type pumps can handle large volumes of air in the case of long suction lines and can often be used where dry running (ie intermittent incoming flow into the sump) occurs.

How do wet prime pumps actually prime their suction lines?

Centrifugal action creates a low pressure point at the eye of the impeller, the partially full casing throws a mixture of air and water into the priming chamber (an integral part of the pump casing), the water in that chamber recirculates back into the suction via a port at the bottom of the casing, whilst the air rises to the top of the priming chamber to be vented off via the air release line or discharge system. This process continues until all the air is evacuated from the suction system, at which point the pump is able to develop discharge pressure and lift the discharge non return valve.

Cornell Food Pumps

Why should hydro-transport systems be used instead of conveyors?

Hydro-transport systems provide a gentle way of cushioning product with water and keeping it fresh whilst being conveyed. It can also be used for retention for blanching processes at the same time. The gentle handling of hydro-transport systems usually provides far less product damage than conveyor systems.

What water to product ratio should be used?

This varies with the type of product. Fragile products like string beans and long potato chips require higher ratios than more robust products like peas, cherries and whole potatoes. The range is typically from 8 to 25 litres of water to each 1kg of product.

What flow velocity should be used?

This varies with product density (heavier products need greater flow velocity to stop them dropping out of suspension, ie settling in the pipework). Generally velocities should be between 1.5 m/s and 2.4 m/s. If they too low, then the pipework will become blocked with product, if they are too high, an increase in product damage occurs and it’s a waste of power by the pumps systems.

What is better on food pumps, mechanical seals or packed glands?

Mechanical seals require less maintenance. Packed glands need to be maintained as the packing wears down to prevent excessive water leakage, but have the advantage of being suitable for even the most fines laden water without requiring flush systems as mechanical seals do in that case. With a failed mechanical seal, it’s quite a major task to change that item. With a packed gland, usually the pump can be re-packed quickly in-situ to keep it going on the current production run.

Cornell Hot Oil Pumps

What’s the maximum temperature of oil you can handle in a Cornell hot oil pump?

Generally that’s 230 degrees C, although most snack or potato crisp fryers run a temperatures less than that (typically 180 to 190 degrees C). For temperatures above 203 degrees C, special seal considerations are required. Sometimes steam or water quench / water cooling is used which certainly prolongs the life of the seal.

Do hot oil pumps need to be stainless steel?

No, most hot oil pumps are built from cast iron / ductile iron / steel parts.

Do hot oil pumps require special sealing considerations?

Yes, the seals need to be capable of handling liquids from 180 degrees upwards requiring special features and materials. Most standard mechanical seals are not suitable. Cornell pumps either use metal bellows type 609 seals or ICS2 cartridge seals with Aflas elastomers.

Wallwin Pumps

Our Wallwin pumps are old, why should we not replace them with more modern equipment?

Look at the value the pumps have given in the past. We are often supplying parts for pumps over 50 years old. The pumps were built to be easily repaired with changeable wearing parts. Installing new types of pumps will usually incur large re-design and civils costs. The modern type of pumps (particularly dry well submersibles) may be relatively inexpensive to buy but seldom last long and are often beyond economical repair when they fail

Are all the Wallwin product lines supported?

Yes, we can supply parts for all ranges (mostly from stock).

What are the typical response times for a spare parts enquiry?

We aim to quote within 24 hours provided the customer can provide adequate information to identify the pump.

What information is needed for the pump to be identified?

Serial number and if possible model type are required. If these are not available we can sometimes identify the pump from photos, casting numbers, dimensional details and site name.

What is the typical lead time on spare parts deliveries?

Over 95% of our spare part deliveries are despatched within 48 hours of receiving the order (this includes impellers which may need to be trimmed and re-balanced).

Are replacement pumps (from old lines) still available?

Yes, conventional type dry well pumps (like the 1094-11) are usually available within 1 to 2 working weeks if required. Older type submersible pumps can be replaced with a modern equivalent designed to fit onto the existing guiderail system (the replacement submersibles are built to order and lead time is typically 5 to 7 weeks

Do you offer a repair service on submersible pumps?

We don't offer a repair service to submersibles but we can always recommend an alternative reputable, and experienced firm for you to contact

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