Any inflatable boat owner will sooner or later face a situation where the boat stops holding air, and most often the cause of a leak is not a puncture of the board, but a failure. pump-valveIt's a small but critically important node that keeps the cylinders and the inflatable floor tight.
Understanding how this mechanism works allows you to quickly fix a malfunction on the shore or in the garage without resorting to the services of service centers. Unlike a simple hole with a plug, modern valves are complex engineering solutions that prevent air from returning.
In this article, we will discuss in detail the design of the different types of connections, their differences and how to work, you will learn why some valves poison the air at high temperatures and how to properly replace the damaged element so that your boat is reliable again.
Purpose and operation of the inflatable valve
The valve's main function is to one-way air through the cylinder, where the pressure opens the passageway when the cylinder is pumped, and when the flow stops, it blocks it, but simply locking it is not enough: the device must withstand high operating pressures, which in PVC tubes can reach 250 mbar and above.
Tightness This is achieved by the elastic gasket and the downforce created by the pressure difference between the inside and outside of the cylinder, and the design is designed to press the valve tighter with the outside air or water pressure, preventing leakage, which is especially important when floating on a wave, when there are dynamic loads on board.
And many of the models that we've got today are equipped with a pressure-emitting function, and when you heat it up in the sun, the air expands, and if you don't let it out, the seams can break apart. discharge or manual release through the central part to avoid bloating the boat.
Main types of connections: Swallow tail and Boat
The inflatable boat market is dominated by two major valve mounting standards. Swallow's tail (or Duckbill), is a cone-shaped insert with an expanding base. Boat valve (Boat valve), which has a cylindrical shape with threading or bayonet mounting.
Swallow tail valves are more common on budget models and older boats, requiring warm-up and gluing, making replacement difficult without special equipment, while threaded boat valves allow the core or entire assembly to be changed with a simple key.
It is important to note that seat diameters may vary. Standard dimensions vary, but the most common base diameters are around 40 mm. Before buying a spare part, you need to accurately measure the seat, because the seat is very small. Incompatibility of diameters even 1-2 mm will make the installation impossible.
The design of the valve: what it consists of
When you take the valve apart, you'll see several key components, each of which has a different function, and understanding their function will help diagnose the malfunction, and the main elements are the body, the center stem, the spring and the sealing cuff.
The body serves as a base that is glued into the PVC fabric, and a spring-loaded mechanism moves inside it. spring This allows the valve to return to a closed state after inflating, and if the spring is weakened or rusted, the valve can bend.
A sealing cuff is a rubber or silicone ring that comes in direct contact with the valve seat, and it's the wear and tear of this part that most often leads to etching air. ventilator, regulating pressure.
⚠️ Warning: Never attempt to lubricate the valve's internal mechanisms with oil lubricants or WD-40. Aggressive chemistry can destroy rubber seals and PVC fabric, making the valve completely inoperable.
Instructions for valve replacement on PVC boat
The replacement process requires precision and temperature control. If you're going to replace a Swallow tail valve, you're going to need a hair dryer, a special PVC glue and a roller. Carving models will require a key holder and a sealant.
First, you have to de-grease the boat completely and de-grease the area around the old valve, carefully cut out the damaged element, trying not to damage the inner layers of the cylinder tissue, clean the edges of the hole and prime.
The new valve is inserted into the hole, and the legs are extended inside the balloon, and the adhesive is applied on the outside, and then a patch of PVC tissue is applied. roll in edges to avoid air bubbles.
☑️ Valve replacement tools
Once installed, the glue must be allowed to fully polymerize, which usually takes 12 to 24 hours depending on the ambient temperature, and early pumping can lead to the edges detachment and re-leakage.
Comparison of specifications of different models
When choosing a spare part, it is important to consider not only the type of connection, but also the materials of execution. Other manufacturers use different alloys and polymers, which affects the durability of the unit.
| Parameter | Swallow's tail | Boat threaded | Auto-launch valve |
|---|---|---|---|
| Difficulty replacing | High (glue required) | Low (key) | Medium |
| Tightness | High. | Depends on the thread. | High. |
| Price. | Low. | Medium | High. |
| Repairability | Low. | High. | Medium |
As you can see from the table, threaded models benefit in ease of service, but may be inferior in the final tightness if the thread is loosened. Auto-pressure-relief valves are the premium segment that provides maximum safety.
Owners often experience a situation where the boat is poisoning in hot weather, and this is due to the physics of gases: when heated, the air volume increases, and if the valve does not have an etching function or it is blocked, the pressure can exceed the critical value.
Typical malfunctions and methods of their elimination
The most common problem is mechanical injury Sand, fine dirt or salt caught between the saddle and the gasket, violate the tightness, in which case it is enough to thoroughly wash the valve with fresh water.
The second is the deformation of the valve body, which can happen when you're not transporting the boat properly or storing it in compressed condition under the weight of other objects, and if the plastic case is cracked, all you can do is replace the unit completely.
⚠️ Warning: If you find that the valve is leaking air under water (bubbles come from under the base), do not try to seal it outside while the boat is inflated. Air pressure will not allow the glue to grasp, and after blowing away the glue will go away.
There is also oxidation of the spring mechanism, especially in models with metal elements. The rust blocks the movement of the rod, and the valve stops closing completely. In such cases, it is recommended to use specialized silicone lubricants that are safe for PVC.
Regular prevention prolongs the life of the valve. After each fishing, it is recommended to wipe the valves with dry rags and cover them with protective caps so that dust and insects do not get stuffed inside.
FAQ: Frequently asked questions
Can I replace the "Swallow's tail" valve with a threaded one?
It's theoretically possible, but it requires a lot of reworking, so you have to cut out the old valve, patch the hole, and then put a new valve in a new place (or the same place if the diameters match), and it's easier to buy the same valve that was there in the first place.
Why does the valve let air through when the boat is just lying in the garage?
The problem is likely to be contamination of the sealing cuff or its natural aging (loss of elasticity), and check if the protective cap is tightly twisted, as it is involved in sealing in some models.
Which glue is best for sticking the valve?
Use only two-component polyurethane adhesives specifically for PVC (e.g. Texacol, Kleyberg or specialized adhesives from boat manufacturers). A conventional "moment" or rubber adhesive will not provide the necessary strength and elasticity of the seam.
How do you know if it’s time to change the valve?
If after careful washing and lubrication, the valve continues to poison, or if the plastic case has visible cracks and deformities, it must be replaced, ignoring the problem will make it impossible to pump the boat to working pressure.