HOME

Company

Information

 

ABOUT US

 

OUR POLICIES

Ordering, Payment,

Shipping, Customer Service, and Dealer Information

                    

SERVICES

Helmet Repairs, Custom Helmets, Inspections

 

NEWS

as of 12/11/14

 

LINKS

 


Current

DESCO

Products

 

DESCO HELMETS

All current production

DESCO helmets

 

DESCO MASKS

Commercial and Pool

Cleaning Masks

Light Duty Diving Outfit

 

FITTINGS & TOOLS

Adapters, couplers & wrenches

 

DIVER ACCESSORIES

Divers Knife, Shoes, 

Weight Belts

 

COMMUNICATIONS

DESCO Two Diver

Telephone and available communications options

 

IN STOCK

as of 12/08/14

 

RETAIL

PRICE LISTS

Current DESCO,  CBE, & Viking price lists.

 

Current

Third Party

Products

 

DRYSUITS

Third party dry suits

sold by DESCO

 

DEEPSEA B-2 HELMET

Composite Beat Engel

Demand Helmet

 


Product

Support 

 

SAFETY

Update 11-22-12 

 

TECHNICAL INFORMATION

Product warnings and

cautionary notes

 

DIVING REGULATIONS

OSHA, USCG,

USACE, USN

 

DOWNLOADS

Manuals & service guides

 

PRODUCT SPECIFICATIONS

 

 


General Diving & Equipment

 Information

 

SURFACE SUPPLIED DIVING

What gear it takes to dive.

 

CONTAMINATED WATER DIVING

 

HELMET CONSTRUCTION

What goes into making

a diving helmet

 

HELMET IDENTIFICATION

Real or Replica?

 

HELMET DETAILS

Features of the various

helmet models

 

 


History

 

COMPANY HISTORY

How DESCO started

 

DESCO PEOPLE

Those who built DESCO

 

DESCO PRODUCT HISTORY

General product history. Catalogs, significant orders, etc.

 

OLD EQUIPMENT

Discontinued DESCO Products

 

MIXED GAS & REBREATHERS

DESCO A, B, C Rebreathers Recirculating Helmets 

 

DESCO SPORTING GOODS

SCUBA Lungs, Water Skis, and Miscellaneous Water Sports Products

 

US NAVY MARK V

100 ANNIVERSARY

 


Galleries

 

MEDIA

Magazine or News

articles related to diving.

Links to online diving videos.

 

GALLERY 1

DESCO company photos

and photos from our archives

 

GALLERY 2

Commercial Diving Photos supplied by customers

 

GALLERY 3

Classic equipment &

hobby diving photos

 

GALLERY 4

Photos of helmets from

other manufacturers

 

GALLERY 5

Photos of equipment

 in museums

 

GALLERY 6

Photos from some of

our repair projects

 

GALLERY 7

DESCO Historical Item Collection

 

GALLERY 8

Miscellaneous Photos,

Old diver and/or equipment photos

 

 

Diving Helmet Details

The various features on different style diving helmets.

For helmet communications details please see the COMMUNICATIONS page.


    Exhaust Valves


 

Exhaust Valves

We're starting with exhaust valves as there is more variety in this component than any other.

 

Exhaust valves are an essential component of the helmet as what goes in must come out. Differences in exhaust valves are mainly in the location and the amount of control they provide. Also the point at which the gas escapes the valve may differ considerably.

 

The Sponge Helmet Exhaust Valve

 

     

 

This is the most basic exhaust valve design. The Sponge Helmet exhaust is a single spring, non-adjustable, head butt valve mounted on the right rear of the helmet top. One spring applies pressure to the valve stem to hold the predetermined overpressure in the suit. The valve does not have any ducting and vents through holes spaced around the perimeter. The suit can be "dumped" by opening the valve all the way using the back of the head against the button on the valve stem.

 

The Agar Helmet Exhaust Valve

 

   

 

 

The Agar Helmet exhaust is a single spring, adjustable, head butt valve mounted in the same location as the Sponge Helmet exhaust. The central body is cut from a Mark V exhaust banana casting. The "bonnet" is male threaded and the body is female threaded, which is reverse of a Mark V exhaust valve. The Star wheel is a Mark V casting without the internal threading for the spring retainer. It is held in the bonnet by a stop ring soldered on after assembly. A duct extends downward with vent holes drilled along the perimeter and on the face.

 

 

The Abalone Helmet Exhaust Valve

 

      

 

The original design of the Abalone Helmet called for an exhaust valve which was a combination of the USN Mark V valve banana and the Agar single spring valve. Later (and current) Abalone helmets use the standard Mark V double spring exhaust valve. The "banana" tube vents the helmet behind the right side window to prevent the escaping air obscuring the divers view.

 

 

The Browne Commercial Helmet Exhaust Valve

 

 

 

The Browne Commercial Helmet exhaust valve is actually a double exhaust valve. The primary exhaust is a standard USN Mark V valve assembly with a secondary, non-adjustable, rubber flapper exhaust valve in it's own housing. The two valves are joined by a duct. The helmet vents through holes in the perimeter of the secondary exhaust cover. The suit can be dumped by activating the valve with the back of the head.

 

 

 

The US Navy Mark V Exhaust Valve

 

   

 

The US Navy Mark V Helmet exhaust is a double spring, adjustable, chin activated valve. When the star wheel is fully closed the secondary spring provide the preset cracking pressure for the valve. This allows for pre determining how much overpressure will be in the suit at fully closed. The "banana" tube vents the helmet behind the right side window to prevent the escaping air obscuring the divers view.

 

 

 

The US Navy Helium Helmet Exhaust Valve(s)

 

 

 

The US Navy Helium Helmet Exhaust Valve has two versions. The early helmets had a exhaust duct which ended in a bulb just like the banana tube. This duct rose vertically from the main body over the top of the helmet and terminated near the elbows. It was found that salt water could leak back into the helmet. If this water were to mix with the CO2 absorbent it would form chlorine gas. In the early 1950's the design was changed to add an additional non-adjustable double exhaust valve on the top of the helmet. This in essence made the valve a "triple exhaust". The primary valve is a standard Mark V assembly.

 

 

The Browne Utility Helmet Exhaust Valve

 

 

  

 

The Browne Utility Helmet exhaust is a double spring, adjustable, double exhaust valve. The primary valve assembly is standard USN Mark V, and the non-adjustable secondary valve is a rubber faced Brass disk with a single spring. The valve vents out four large holes in the secondary valve cover.