Holding Tank Plumbing Layouts

Welcome to our Holding Tanks Plumbing Layout page, here you will find above and below the waterline plumbing layouts. Please Take a look out our top tips and Q&A section which if followed will ensure that your waste system will not only work efficiently it will also provide you with many years trouble-free service.

Simplicity at its best!

The gravity discharge system is easy to install simple pipework and no pump to worry about. For gravity to do its job the tank needs to be no less than 100 mm above the waterline.

On waste tanks we recommend using 1 ½” fittings throughout. On a gravity tank a 1 ½” outlet works well but a 2” outlet would work better providing twice the cross-section area.

If you decided to go with a 2” outlet, then you will probably need to change the Seacock as well, most black waste seacocks are 1 ½” as standard.

To ensure against waste and odor leaks double clip all hose connection.

If you can, use swept bends instead of 90° elbows.

Tanks above the waterline.

The following pictures show various diagrams for tanks positioned above the waterline. Use these diagrams as a guide or starting point. We are always on the end of the phone and would be pleased to discuss your needs.

Gravity Discharge with Charcoal Vent and Deck Pumpout
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Gravity Discharge with Charcoal Vent and Diverter Valve
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Gravity Discharge with Charcoal Vent, Deck Pumpout and Diverter Valve
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Gravity Discharge with Charcoal Vent
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Manual Pump with Charcoal Vent, Deck Pumpout and Ball Valve
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Manual Pump with Charcoal Vent, Deck Pumpout and Dip-Pipe Outlet
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System Accessories

Click here for information on all plumbing system accessories

Tanks below the waterline.

The following pictures show various diagrams for tanks positioned above the waterline. Use these diagrams as a guide or starting point. We are always on the end of the phone and would be pleased to discuss your needs.

Manual Pump with Charcoal Vent, Diverter Valve and Ball Valve Tap
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Manual Pump with Charcoal Vent, Diverter Valve and Dip-Pipe Outlet
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Manual Pump with Charcoal Vent rand Ball Valve Tap
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Manual Pump with Charcoal Vent and Dip-Pipe Outlet
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Manual Pump with Charcoal Vent, Diverter Valve, Deck Pumpout and Ball Valve
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Manual Pump with Charcoal Vent, Diverter Valve, Deck Pumpout and Dip-Pipe Outlet
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Below Waterline Drawings

Macerator Pump with Charcoal Vent, Non-Return Valve, Diverter Valve and Deck Pumpout
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Electric Pump with Charcoal Vent, Diverter Valve and Deck Pumpout
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Manual Pump with Charcoal Vent, Diverter Valve and Deck Pumpout
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Manual Pump with Charcoal Vent
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Manual Pump with Charcoal Vent and Deck Pumpout
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Manual Pump with Charcoal Vent and Diverter Valve
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Question & Answers

Q: What fittings do I need on a black waste holding tank?
A: A standard waste tank would normally have a Inlet coming from the toilet, a deck pump out fitting complete with a dip pipe, a vent fitting and a discharge outlet to sea.

Q: In general, what size fittings would you recommend on a waste tank?
A: We recommend 1 ½” 38mm elbows or straight hosetail fittings throughout.

Q: How high does an anti-syphon loop need to be?
A: On a sailing boat taking the yachts heal into consideration the anti -syphon ideally needs to be 250mm (10”) above the water line. If the tank or toilet is either on or below the waterline then the system should be treated as below the waterline.

Q: Why and when do I need to have a loop in my pipes?
A: When the inlet or outlet hoses are plumbed overboard, below the waterline and terminating inboard below the waterline, they must be looped above the waterline to prevent siphoning.

Q: Why do you recommend an 1 ½” vent for a black waste tank?
A: Sewage contains aerobic bacteria which breaks down the waste and anaerobic bacteria which produces the smell. The aerobic bacteria need a good flow of oxygen to survive and an 1 ½” fitting provides this. Whereas anaerobic bacteria thrive in an airless environment so the oxygen in the tank keeps this bacteria and subsequent odor at bay.

Q: Do I need a Charcoal Vent?
A: When the toilet is being used or in heavy seas its is possible for odor to pass over the boat. If you have a decent tank vent odor is kept to a minimum. You could just fit one or retro fit one if the issue arises. Charcoal filters are quite large take a look at the Pong Go charcoal filter

Q: What sanitation hose is best?
A: Sanitation hose varies in quality which is largely indicated by its price the more you spend the better the hose. A reasonable quality white PVC hose should have antibacterial chemicals within the material and this should marked as such on the hose. A butyl rubber hose is better Tek Tanks keep a 5 year and 10-year warranty hose.

If you would like to discuss your holding tank need the accessories’ required pleas do not hesitate to contact one our extremely experience team. TEL: 01420 520830

Address

Tek Tanks Ltd

The Old Stables, West End Farm,
Upper Froyle, Alton, Hampshire,

GU34 4JR England

Tel: +44 (0)1420 520830

Email:  sales@tek-tanks.com

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