Chris 07944272926

Click to Search 
Search Regulator servicing specialists Scubaworkshopuk Rebreather valve servicing Y valve servicing H valve servicing J valve servicing Isolation valve servicing Manifold valve servicing

This is the thread inside the valve which the 1st stage screws into.

With a din insert you can convert it to accept an A clamp fitting.

Din convertable valve serviced Din insert M26 Valve Servicing A clap valve servicing Din insert in a valve Apeks valves serviced San o sub  valves serviced MDE valves serviced Problems with Valves,Give us a ring….


Outlets on valves

5/8 DIN

These valves allow many combinations by fitting a Manifold ,H Valve, Y Valve Adaptor or End Caps.

The cylinder valves are available in Left or Right hand versions, these can be used for easy use of stage cylinders or side mount diving

Din Insert.

This has a hexagonal hole in the centre with which to remove it.

A Clamp

This has no removable insert.

New M26

Nitrox fitting.

This is for use on nitrox and trimix cylinders.

This is bigger than 5/8’s DIN

(cannot use din insert)

M25 gauged valve

Cylinder Valve Threads Explained.

This is the part that screws into the cylinder They are generally described by there diameter , which is the same all the way down the valve.



M26, M25, M18, M14

Based on the diameter of the thread

i.e 25mm diameter M25

      14mm diameter M14


G ¾ BSP (Older Valves)

¾ MPSM (Some American Valves)

These are ¾ of an inch in diameter and the letters denote the profile of the thread.

(These MUST not be fitted to M25 cylinders as they do not fit properly but will screw in).

Taper gauged valve


These threads are cut in a cone shape. The diameter of the thread at the top , is a lot larger than the bottom.

It “Tapers” down to the bottom.These are common sizes 19.8,.715 and .600

Note these threads can only be differentiated by using gauges.

Different types of Valves

All the valves on this page are known as K Valves.

Except this one :

J Valve.

These are quite rare, they have a lever assembly that when pulled will give a reserve of 50 bar.

This was used before the introduction of SPG’s.

(The reserve only worked if it was reset before filling)

T or  Rebreather Valve.

As they are commonly used on Rebreathers.

“H” and “Y” Valves.

These are very similar, the H is movable

and the Y is fixed.

You can attach two 1st stages and be able to isolate either one if needs be.

Twinset Manifold.

This connects two cylinders and effectively makes them one, and you can attach two 1st stages.

This plain type is called a “Live” Bar.

Twinset Manifold with Isolator.

This is the same as the manifold,but you can isolate one cylinder from the other.

So either of the 1st stages or valves can be isolated if the is a problem with a 1st stage or valve.

The use of these valves underwater is known as a “shut down drill”.

Modular Valves.

Modular valve servicing Modular valve plug Left hand modular valve

Single Cylinder Left or Right Hand

H valve add on right hand modular valve H valve assembled

Single Cylinder “H” Valve

left hand manifold valve isolation manifold Plain Manifold left hand manifold valve

Twinset Manifold with “Live” bar or Isolator

M26 Nitrox

What is a M26 Valve?

This is the type of scuba cylinder valve that must be fitted to any new cylinder that is going to be used with any gas greater than 22% oxygen, this is a European directive that came into force in August 2008.

This will match any regulator supplied in the European Union which has been designated for use with gas containing an oxygen content greater than 22%.

In simple terms if you buy a new set of regulators for nitrox use they will come with a M26 fitting and if you buy a new cylinder for nitrox use then it will come fitted with a M26 valve.

We are fully equipped to service clean and test your M26 valves and regulators.

If you are buying a new valve and cylinder we would recommend that you get the valve threads "Gauged" to ensure the quality of the valve your buying.

( this is where the valve threads are checked against a certified standard gauge)

What's it look like?

It looks similar to the Din type of valve, just slightly bigger.

The valve should have the information stamped or etched on the valve itself.

5/8ths Din

This is smaller in the Cylinder valve and the regulator.

(Approximately 15mm Diameter)


This is Larger in the Cylinder valve and the regulator.

(26mm Diameter)