The elastic pressure chamber water blaster technology is analogous to separate air-pressure chamber water blaster technology, but instead of relying on pressurized air, an elastic material is used instead to pressurize the chamber and water within. As with separate pressure chamber systems, water is pushed into a pressure chamber to create the pressure. Unlike air-pressure chambers, the water-accessible volume in an elastic pressure chamber increases as more water enters. Because of the nature of the elastic materials used, fewer pumps are needed to achieve good stream performance from these types of chambers.
There are three or four primary types of elastic bladders used (and an additional one depending on how you define things):
- Full Rubber Bladder - these are the type used in the Super Soaker CPS series and in some other models
- Spherical Bladder - these full rubber bladders have a spherical shape
- Cylindrical - these full rubber bladders have a cylindrical shape
- Diaphragm Bladder - these hemispherical-shaped bladders were used first by the Water Warriors brand
- Spring-Based - there are a number of water blasters that have used springs with plungers to propel water
- *Air-Pressure-Sliding Plunger Based - these blasters have a sliding plunger that separates the pressurized air from the water and was used by the Water Warriors Aqua Master PreCharger system. Due to the configuration, this system behaves similarly to the other elastic-material-based systems.
* Note: granted, while compressed air does not completely behave like expanded rubber bladders or a compressed spring, the separation between the water and the pressurized section offers better stream performance while eliminating mist-shot issues.
The elastic pressure chamber water blasters' workings are comprised of seven (7) to ten (10) types of parts:
- Pump Grip - where the user holds onto the sliding inner section of the pump
- Pump Rod - the part of the pump that slides within the pump shaft
- Pump Shaft - the outer casing of the pump that holds water
- Nozzle - where water exits the water blaster
- Check Valves #1 and #2 - one-way valves to control the direction of water flow from the reservoir to the pump, then to the nozzle
- Connective Tubing - for connecting the other parts together in a specific arrangement
- Elastic Pressure Chamber - where water is stored under pressure prior to firing and creating the stream
- Reservoir - water and pressure storage compartment
- Relief Valve - allows excess pressure to be released safely well before other pressurized parts are likely to fail
- Connective Tubing - joining the various parts together in a specific order
Example Water Blasters:
The following are some examples of water blasters that use separate air pressure chamber water blaster technology:
- Super Soaker CPS 1000 - spherical full bladder
- Super Soaker CPS 2000 - cylindrical full bladder
- Water Warriors Blazer - diaphragm bladder
- Water Warriors Pulse Master - spring-based
The Water Blasting Cycle:
While performance between the different elastic systems does vary, the overall operation of any elastic-based water blaster remains the same. As such, for simplicity sake, all will be discussed in this article with notable differences highlighted as needed, but only diagrams for the spherical full bladder and diaphragm systems will be shown. The steps involved when using these types of water blaster are detailed below:
Step 1: Priming
To prime, as with separate air pressure chamber water blasters, the pump should be pushed in, forcing any residual air through Check Valve #2 and into the pressure chamber. While there are some nozzle valve differences between various water blaster models that use a elastic pressure chambers, these minor differences will not be discussed in this article since the overall operation remains the same.
For optimal performance, opposite to separate air pressure chamber water blasters, it is best to remove any lingering air in the elastic pressure chamber before pumping in water. While not necessary, doing so usually improves stream performance throughout the duration of the shot. To expel trapped air, water first needs to be pumped into the elastic pressure chamber. With some water present, the blaster should be held at an angle such that the port or opening of the elastic pressure chamber is facing upwards since air will float to the top of the water (Note: the usual direction is nozzle pointed upwards, but in some cases, one needs to consider the direction of the pressure chamber's opening). Once in position, the blaster's trigger should be pulled briefly to allow the air to escape. For best results, this should be repeated until no air remains present in the elastic pressure chamber.
* Note: for the split air/water-based systems (e.g. Aqua Master PreCharger water blasters), priming is a little more complicated. The back side of the chamber (where the air goes) should be pressurized to some degree before water is pumped into the front side. To do this, these blasters have a button on their side which needs to be depressed, allow the pump to push air into the rear of the pressure chamber. Once enough air was pushed in, the button would automatically pop out, switch the pump into water-pumping mode.
Step 2: Loading
Akin to pump action, syringe, and trigger pump-based water blasters, extending the pump draws water from the reservoir through Check Valve #1 into the Pump shaft. This, of course, requires that the intake within the reservoir is submerged underwater.
Step 3: Pressurizing
As with separate air pressure chamber water blasters, pushing the Pump Rod back into the water-filled Pump Shaft does not necessarily produce a stream right away. One can hold the trigger down when pumping water and get water to exit the nozzle, but in most cases, stream performance will vary wildly with each stroke. Instead, in typical use cases, water from the pump is used to build pressure within the elastic pressure chamber.
Pushing the Pump Rod into the water-filled Pump Shaft forces water through Check Valve #2 and into the elastic pressure chamber, expanding the material (or pushing the plunger back for spring and split air/water-based systems). As more water is pumped from the reservoir into the pressure chamber, the more the elastic material is pressurized. While more energy is stored as water is pumped in, due to the nature of elastic materials, the pressure exerted by the material on the water remains much more constant, especially when compared to the pressure increases when air is being compressed. Since the maximum volume of the pressure chamber is typically smaller then the reservoir, water is mostly non-compressible, and pressure exerted on the water is fairly constant as soon as the elastic material is extended to some degree, the number of pumps required to build adequate blasting pressure remains is usually much lower than that of even separate air pressure chamber water blasters. While one or two pumps into an other empty pressure chamber is usually not enough, 3-5 is often enough to allow a short burst of decent range to be created if needed.
Additional Diagrams for Other Elastic Systems:
Step 4: Blasting
Akin to pressurized reservoir water blasters and separate air pressure chamber water blasters, blasting is typically done through the activation of some form of trigger. Pulling (or pushing in some cases) the trigger will open the trigger/nozzle valve, creating a path for the pressurized water in the separate air pressure chamber to exit via the nozzle. The force of the stream exiting the nozzle depends on a number of factors including the pressure difference between inside and outside the pressure chamber, the inner diameter of the connective tubing, the distance from the pressure chamber to the nozzle, the inner diameter of the trigger/nozzle valve, stream lamination, and the compression ratio of the nozzle, itself. Since only water is pushed from the nozzle, there is no need for the User to worry about releasing pressurized air.
The requirement for keeping the intake port underwater results in something we refer to as a Firing Angle Limit. In the case of elastic pressure-based water blasters, unlike pressurized reservoir water blasters and separate air pressure chamber water blasters, there is no Firing Angle Limit since there is no air (needed) in the pressure chamber. While there may be some air trapped in the elastic pressure chamber if the blaster was not primed completely, the air is not necessary and is somewhat detrimental to actual stream performance.
Of course, while there is no Firing Angle Limit, there is a Filling Angle Limit in that the intake in the reservoir must remain below water for the pressure chamber to be refilled with water.
Other Flow Path: Over-Pressure
In virtually all modern water blasters, there is a Pressure Relief Valve that is designed to allow the pressurized water to escape in a controlled fashion to prevent over-pressurization and possible structural failure of the pressure chamber and/or pressurized connected parts. Most modern blasters incorporate the Relief Valve together with the Check Valve assembly, allowing water to flow back into the Reservoir instead of our of the blaster. This both saves water from being wasted as well as from other internals (and the User) from getting unnecessarily wet from a dribbling water blaster.
The Pressure Relief Valve works by using a pressure-calibrated spring that holds a plunger in a closed position. In the event there is more pressure in the Separate Pressure Chamber than what the spring is calibrated for, the greater pressure will force the valve open, allowing water to escape through the Pressure Relief Valve, preventing over-pressurization and possible elastic pressure chamber rupture.
Insights on this Technology
Elastic pressure chamber-based water blaster technology represents an evolution in water blaster technology from the separate air pressure chamber water blasters. While many may be familiar with untied water balloons being able to squirt out water some distance, the use of thicker, higher performance rubber and spring-based chambers allow these types of water blasters to push more water further than any system before.
Being manually pumped, these pressurized reservoir systems need no batteries to function. Since it is the pressure chamber that stores the pressurized water, the reservoir can be completely filled (no room for air needs to be left) and the water blaster can even be over-filled/topped off after pumping water from the reservoir into the pressure chamber for the first time. Of course, there must be an air inlet into the reservoir, otherwise as water is pumped out of the reservoir, it will end up negatively pressurized relative to the surrounding air and may end up collapsing inwards.
As with pressurized reservoir water blasters and separate air pressure chamber water blasters, once pressurized, elastic pressure chamber water blasters can be used single-handedly (though many blasters that have a separate pressure chambers also tend to be larger and heavier when fully loaded, thus not easily wielded with one hand). The fact that only the trigger needs to be pulled allows much better stability and accuracy when tracking and targeting one’s opponents, vastly improving aim over the two-handed pump-action water blasters. Moreover, the amount of water that can be expelled by pulling the trigger is orders of magnitude larger than any trigger-pump-based water blasters when properly pressurized.
Unlike pressurized reservoir water blasters that typically require more pumps to pressurize well, the fact that the elastic chamber exerts a fairly constant pressure once one initiates filling, much fewer pumps are needed to achieve good stream power. Of course, the drawback is that since less water is being pressurized at any given time, the amount of total shot time per blast is also reduced. That said, since less pumps are needed and the reservoir holds additional water, often enough to completely fill the pressure chamber 3-4 times, one is never without the ability to blast again for very long.
Of course, in order for the system to become pressurized, there can be no significant leakage of the pressurized water. Check valves, the pressure chamber(s), and internals must be sealed securely. Since the bulk of the pressurized components are internal and do not need the User to adjust, there is less requirement by the User to ensure parts are sealed. As the User typically only interacts with the pump, trigger, and filling the reservoir, so long as the water blaster was manufactured well, there is less chance in for a separate pressure chamber-based water blaster to have leaks due to the User not tightening parts.
One other issue with the fact these blasters are pressurized is the issue of over-pressurizing the internal system. If a relief valve or pressure release is not functional, there is the chance that one can pump too much air into the system, causing parts of the internals to rupture and fail, resulting in leaks or even ejected pieces.
In terms of stream generation, the power of the stream depends on a number of factors:
- the amount of water available: the more water available for the stream, the larger and stronger the stream can be
- the pressure level: higher pressure means more force available to push the water out
- priming the elastic pressure chamber to remove trapped air offers better stream performance since the force applied by the chamber can remain more constant throughout the shot
- the inner diameter of the tubing and nozzle valve: the larger the tubing, the easier it is for water to flow from the reservoir to the nozzle
- the length of tubing between the pressure chamber and the nozzle: longer tubing slows water down more since there is drag from the walls
- the size and compression ratio of the nozzle: optimal nozzle geometry can significantly improve stream performance. Nozzle technology will be the subject of a different article.
Overall, separate air pressure chamber water blaster technology represents the logical evolution from pressurized reservoir water blasters. The Super Soaker 100 is the first stock water blaster known that makes use of this technology. There is a fine balance between acceptable pump volumes and how much pressure chamber volume must be pressurized. The internal set-up also paved the way for non-air-pressure systems to be developed.
- Elastic-pressure-based technology provides more power through the lifetime of the water stream
- Continuous streams with good power possible
- Very good amounts of water able to be blasted out with a single shot
- Even larger elastic reservoirs can be used since the water blaster is able to blast after only a small number of pumps; the additional volume allows for longer blasts, but does not prevent quick response time if needed
- Trigger-based stream actuation improves aiming accuracy
- Reservoir can be completely filled, pressure chamber pumped, then reservoir topped off again to maximize available water capacity
- Must be pressurized (pumped) before a stream can be produced
- Internals must remain water-tight; leaks will result in lost pressure and reduced stream potency