Project Description

Clever Wastewater Pumps enable School Refurbishment

Ty Gwyn Special School in Cardiff have recently modified their sports facility to incorporate 3 classrooms and numerous ancillary spaces including staff rooms and pupil shower facilities.

The old 1960’s sports hall has been divided in two and the best practical design for both staff and children meant the staff kitchen and additional shower room needed to be introduced into the centre of the space. However, this placed them too far from the existing sewer to allow any gravity drainage.

In the new location the wastewater from the staff kitchen area (which included a sink and dishwasher) needed to travel through a waste discharge pipe which would be routed 3 meters high into the new ceiling void and then fall for a length of 10 meters into the nearest gravity drain.

Ian Mullett, Owner of W. Mullett Ltd, was responsible for providing the installation of the services for this project.

He says “We contacted specialist Pump Technology Ltd. because we required a simple yet compact and rugged pumping solution. The system needed to cope with food debris and relatively hot wastewater from the dishwasher, but also be installed inside a kitchen cupboard”

A DrainMinor SL kitchen sink pump was selected. This waste pump for sink unit is designed to fit in a cupboard or under a counter and the lid can be easily removed so the pumping system can be inspected as and when required without the need for any tools.

The SL designation means the collecting tank is fitted with a Jung Pumpen U3K Spezial submersible pump, manufactured in Germany. This features a large triangular float on a rigid arm external to the pump body, ensuring minimum residual wastewater is left in the tank. This greatly reduces the potential for stagnation when the system is not regularly used.

A key feature of this well proven kitchen sink pump is the fact that it is fitted with a mechanical shaft seal rather than a stationary lip seal arrangement. This means that the submersible pump electric motor is better protected from water ingress. This mechanical seal arrangement has proved superior for higher wastewater temperatures and mitigating against damage from food waste such as coffee granules and milk skin.

Ian comments “Due to the sensitive nature of the school, maintenance access has to be planned well in advance, therefore all mechanical pumping equipment needs to be as reliable as possible”

The shower which is a walk-in wet room design also required a pumped solution for drainage. This time a Whale Instant Match Premium shower kit was installed.

This widely adopted shower drainage solution is suitable for any mixer shower configuration and the supplied shower floor gully means a step-free showering area is possible.

The Instant Match uses flow sensors to measure flow rate to the shower. This reading is used to adjust the pumps variable speed motor, so shower flow and pumped flow match. There is little or no suction noise from the gully. A timer also means that 15 minutes after operation the pump will re-start and run slowly for a short period to remove any pooled water aiding hygiene and safety. A Non-return valve in the pump head prevents smells from the waste pipe entering the shower area.

Ian says “We discussed the project requirements with the technical team at Pump Technology Ltd. and they sent me a detailed scope of supply with installation instructions for the equipment we discussed. This meant that we were able to purchase the correct equipment with confidence. The installation and the operation of the pumping systems has been a great success”