Urinals and Urinal Cisterns are probably the hardest public toilet fixtures to sell online simply because many people even those who already have them, do not understand how they work or the considerations when ordering. One of the most common areas likely to confuse is urinal flushing, since, unlike a regular toilet, urinals usually do not flush in response to user input.
How a Urinal Flushes depends on the Urinal System Anatomy.
Exposed Cistern Urinal Systems
Exposed Cistern Urinals are designed so that the cistern is wall-mounted externally, on view above the height of the urinals in the washroom. This means the sparge pipes (often also called the flush pipes) are also to be externally mounted and visible on the walls.
Concealed Cistern Urinal Systems
Concealed Cistern Urinals are designed so that the cistern is to be hidden from view, perhaps behind IPS duct wall panels, wall cladding, or within a wall void in the washroom. This means the sparge pipes will also be concealed, running behind the panels or cladding, or within the void.
Urinal Spreaders are Important.
Types of spreaders
Spreaders are connected to the flush pipes and "spread" the water around the whole urinal bowl to ensure a full and clean flush. These are typically included within all the full urinal kits we sell as they are essential for a flushing urinal.
In Exposed Cistern Urinal Kits, these spreaders typically sit on top of the bowl, with the water inlet directly above.
In Concealed Cistern Urinal Kits or mains-flushing urinals, the spreaders typically accept water flow horizontally from behind the urinal. This comes through the wall, wall cladding or panelling and then into a hole in the top of the urinal bowl.
Urinal Flushing Types.
There are three main ways of flushing the waste from a urinal;
- Flushing the urinals via a cistern (auto cistern)
- A direct mains water-fed flush,
- Not to flush the urinal at all, but to install a waterless urinal system
1. Auto-cistern Urinal Flush
An auto-cistern is usually the term used for a urinal cistern. Urinal cisterns, like toilet cisterns, come in plastic or vitreous china; plastic cisterns are typically for concealed installations, i.e., behind wall cladding, ducting, or within a wall void. Vitreous china cisterns are more aesthetically pleasing and are usually used for exposed installations where the sparge pipes and cisterns will be wall-mounted.
Despite the name ‘auto cistern’, there is nothing automatic about them; they are simply a vessel for stored water with which the urinal will flush. The work is in fact all done by an auto syphon, which will release the stored water down into the sparge pipes to flush the urinals once the water level within the cistern has reached a sufficient level. This water level is detected by a float valve.
Without a secondary form of Flush Control, a urinal cistern will continually and rapidly refill, causing unnecessary flushing. In the past, to slow this flushing cycle, a petcock was used in the inlet pipe (which fills the cistern). A petcock is simply a plastic bung placed within the inlet pipe, usually with a screw to adjust the inner aperture of the petcock to adjust the flow of water through it. This restriction in the pipe by the petcock would slow the water entering the cistern, allowing the plumber to adjust the refill rate and thus the flush frequency of the cistern.
As you can appreciate, petcocks are not the ideal solution, as even when a venue or premises is closed or quiet, the flushing interval will not change, resulting in considerable water waste. Hence, for the last few years, the use of a petcock within a urinal flushing system has been outlawed by Schedule 2, section 9, and paragraph 25 of the Water Regulations.
The new and accepted solution and advice are to install an approved Urinal Flush Control with all auto-cisterns and urinals.
Flush controls can be split into 2 broad types: Hydraulic and Sensor.
Hydraulic Valve urinal flush control.
Hydraulic valve urinal flush controls, such as the Cistermiser range, are installed in-line with the water supply inlet pipe into the cistern and sense short-term drops in water supply pressure. Each time a drop in pressure is identified, the valve releases a measured amount of water into the cistern.
These short-term drops in water pressure are caused by tap use or toilet flushing, and while not directly measuring urinal usage, at least refill the cistern at an approximate frequency based on the washroom's overall use. This will reduce flushing frequency when the venue or premises and their washrooms are not in use. Typically, these units can be configured to still allow a janitorial flush every 12 hours to reduce unpleasant odours from urinals, even when the washrooms are not in use.
Hydraulic Valve Urinal Flush Controls will deliver substantial water savings compared to typical petcock-controlled flush cycles and will meet water regulations. There is also a hydraulic valve flush controller to suit any type of water pressure, from standard (tank-fed or mains pressure) to low-pressure tank-fed washrooms.
PIR Sensor urinal flush control.
PIR or Passive Infrared urinal flush controls, like those produced by Dart Valley Systems, can be mounted on pipes, walls, or ceilings and actually sense when a particular urinal or row of urinals is used, unlike a hydraulic valve, which only senses when a washroom as a whole is used.
When the urinals are used, the PIR Sensor Flush control will begin a cistern fill cycle that can take up to 15 minutes, with an adjustable delay before the cycle starts, too. PIR sensor urinal flush controls can also be supplied as downlighters for installation into suspended ceilings, providing a more streamlined aesthetic finish to a commercial washroom space.
Sensor urinal flush controls will also allow a janitorial flush every 12 hours, even when the washroom is not in use, to prevent unpleasant odours. Sensor flush controls can achieve up to 80% water savings on petcock-controlled urinal flush systems and comply with water regulations.
The mains flush can be controlled by a button, sensor, or lever. For the urinal push button and lever flush, depending on preference, the pipework can be run concealed or exposed, and sparge pipes are not required; only normal 15mm or 22mm diameter water piping is required. For sensor mains flush systems, it is preferable to run the pipework in a concealed manner so that the electronics are not exposed to the user.
2. Urinal Mains Water Flushing.
Urinal Mains Water Flushing Sensors are popular in school toilet refurbishments as they are vandal-proof and help save water. They are plumbed directly into a mains water supply and do not need a urinal cistern.
Most urinal bowls can be used with a Mains Flush System, and you will only require the urinal bowl, fixings, brackets and a spreader for a working kit. Examples of urinal flushing kits that plumb directly into a mains water supply include the Armitage Shanks Sensorflow 21 Panel Mounted Mains Urinal Flush Sensor Kit and the Delabie DVS Urinal Sensor Flush Control Kit.
3. Waterless Urinals.
Waterless Urinals are those that do not require flushing by a cistern or water. These are ideal for commercial washrooms that may not have plumbing or space for a high-level cistern, or that face other difficulties in the existing configuration that prohibit the installation of a typical urinal system. However, they still require waste pipes to remove urine.
Waterless urinals typically require more day-to-day maintenance than regular urinals, with chemical cartridges or chemical top-ups required. But as washrooms should be regularly cleaned, this should not pose too much of a difficulty.
There are two types of waterless urinals: those specifically manufactured for waterless use, and regular water-flushing urinals retrofitted to work in a waterless configuration. Both work by neutralising urine odour and preventing it from backing up into the bowl, allowing it to drain away. Waterless urinals should not be used with bottle traps, however.
Urinal Traps
Bottle Trap
Bottle traps are perhaps best known for their use on sinks, and are the most widely used trap for urinals. We strongly recommend white plastic traps for urinals due to the difficulty of keeping chrome-effect bottle traps clean. In the event that the bottle trap, or, in fact, pipework further along the system, becomes blocked, bottle traps can be easier to clear than other types. However, if the urinal flushing system fails for whatever reason, the bottle trap may more readily block or spring a leak than an S or P trap would. They are also not recommended for waterless urinals, as they will store too much waste urine in the bottle portion of the trap since they do not flush.
S-traps and P-traps for Urinals
We do not usually recommend either S-traps or P-traps for urinals or urinal troughs, though they can be used. The reason they may be preferred is that they are free-flowing, and after flushing, the water within the trap will likely be clean water rather than still containing traces of urine, as in a bottle trap. However, with a smaller diameter than the bottle trap and an incorrectly set flush frequency, they will more readily block and be harder and more labour-intensive to clear than a bottle trap.
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