To maintain adequate sanitation, clean fresh water at saturation diving habitat for washing and showering, waste removal from the toilet, is provided. To supply the habitat with freshwater, the water supply pressure must be higher than the inside pressure. To achieve this the water could be put in the pressurized water storage containers that pressurizes the fluid to a pressure greater than the pressure of the habitat. Alternatively, a water pressure booster pump can be used. Cold and hot water are fed from several hull penetration quarter turn valves on the outside and Non Return Valve (NRV) on the inside.
The sanitation system is housed in the Transfer Chamber where the TUP procedures between saturation diving system and closed bells or SPHL take place.
Toilet facilities within a saturation diving habitat include pipes, containers and valves. Specifically after the use of the toilet system a tender operator or ALST will open the external valve (C) for the final drain. Valve (B) inside habitat located after the holding tank near the hull is opened, and then closed. Valve (A) inside habitat, under toilet bowel is opened, allowing the contents to go into the holding tank, subsequently is closed. Valve (B) opened, and then closed. Valve C is then closed. Valves inside habitat (A and B) are operated by the occupants.
Toilet systems provide interlocking valves, a fail-safe device for the controlled opening and closing of valves, to make sure that the toilet cannot be flushed while it is in use.
Massimo Torboli
Diving Safety Officer
Non Return Valve – check valve that allows the flow only in one direction; i.e. it prevents fluid from flowing back.
Simple representation of a Non Return Valve.
It consists of a two opening body huousing the spring and the shutter. When the fluids flow through the valve, it pushes the shutter, opening the valve. When the flow stops, the spring pushes the shutter in its position, closing the valve and avoiding fluid reflux.
Image by Palagiri, from commons.wikimedia.org
Transfer Under Pressure – in hyperbaric units or saturation systems, process that allows people or objects transfer from a compartement to another, while mainteinig pressure.
Self-Propelled Hyperbaric Lifeboat – Specially designed Hyperbaric unit. It allows divers decompression and survival in case of vessel evacuation. Like an HRC (Hyperbaric Rescue Chamber) it floats and can be towed or recovered, but, in addition, it can move by itself, since it is equipped with propellers or thrusters.
Image
Cover: “transport_under_pressure_chamber_inside-nieuw” by courtesy of Royal IHC.
