Hoses
To ensure that a pumping application is successful and efficient it is recommended that good quality hoses and fittings are used.
Most applications using Exsel pumps are temporary, for which the quick release type of hose fitting is best suited. For high pressures or for more long term applications the bolted flange type of rigid steel pipework may also be used.
Layflat hose MUST NOT be used on the suction line for any pump. It may be used for the discharge hose, subject to the pressures being within the hoses specifications.
The medium head range of SPP, Hidrostal & Toyo pumps are normally supplied with quick release fittings on the suction and delivery connections. For high head and flow pumps these fittings must be specified to suit the pump application.
Hoses are vulnerable to damage by crushing and although they may appear to recover their shape, the internal reinforcing wire and inner sleeve may still cause an obstruction to flow. Damaged sections of hose should be replaced immediately.
Flexible hose can be obtained in four main materials:
Hose material must be chosen to suit the liquid being pumped especially when pumping volatile liquids and chemicals. Hoses are normally supplied in convenient lengths for handling and transport. For long hose runs it is better to use one continuous length of hose to minimise friction losses from the hose fittings.
| Rubber | Synthetic rubber with layers of textile and steel reinforcing wires | Ideal for suction and discharge hoses |
| PVC | Smooth bore offers minimum resistance, long runs are useable | Suitable for both suction and discharge hoses |
| Poly Galvanise, Steel tube | Semi-rigid and resistant to damage, lightweight & economical | Ideal for discharge hoses |
| Layflat | Plastic or woven terylene can be used, can kink in use | Only suitable for discharge hoses |
Flexible hoses will move in use and when lying over hard and sharp edges may become frayed and holed. At these points, protection of the hose is advised if an alternative routing is not available. Where convenient a short steel pipe or fitting can be inserted in the hose run at the point where damage may occur. For satisfactory operation it is important to ensure that the suction hose is free from leaks as these will reduce the efficiency of the pump.
