SAFETY PAGE

Diving is a potentially hazardous activity, that if practiced incorrectly or with incomplete planning and procedures can expose a person to considerable risks including serious injury or DEATH. It requires specialized training, equipment, and experience. DESCO recommends the guidelines established by the Association of Diving Contractors Consensus Standards for Commercial Diving Operations, as well as OSHA and USCG Federal Diving Regulations. NOTE: No standard will ever exist which can substitute for common sense, sound judgment, and a continuing concern for maximum safety. SAFETY IS NOT A RULE BOOK. IT IS A STATE OF MIND.

Cold Water Diving

Any air (pneumatic) system given the right combination of temperature and/or airflow has a propensity to freeze up. It is prudent therefore to check for moisture regularly and install a secondary in-line dryer system if necessary. If moisture freeze up problems persist contact your compressor dealer for recommendations to suit your particular needs.

DESCO Air Hat Safety Notices

Safety Issue: Air Distributor Packing (8/13/12)

We receive a air hat from a customer for inspection and repair. He just bought the helmet used and wanted it updated and certified for diving. During evaluation we found several issues of incorrectly installed parts. The most troubling find was what the air distributor was packed with. We can't call it Steel Wool as we have not seen anything this coarse before. when the packing was removed from the air distributor small pieces and particles fell from the housing. Had these bits been blown out into the helmet they could have embedded themselves in the diver's cheek, eyes, or have been inhaled into the lungs. Any one of these injuries could cause a debilitating or life threatening infection. NEVER use any material except Lambswool in the air distributor.

Safety Issue: Air Hat neck ring clamping system.

Last week Ric received a call about a diver who had the lock and the clamp open up on one side of his Air Hat. This is the first instance we can recall of this event happening. The diver was in a confined area with snag hazards. It appears the lock was snagged and opened without the diver knowing. Subsequently the clamp was snagged and opened allowing a few drops of water (as stated by customer) to enter the helmet.

The clamp and lock system on the Air Hat depends upon frictional drag placed on the clamp and lock by the retaining bolts. Nylon washers act as spacer/bearing surfaces to prevent metal on metal. The clamp and lock open in opposite directions making a single snag virtually (never say never) impossible. The customer asked us to develop a spring loaded lock for the situation they are diving in to mitigate this issue. We complied and now have a conversion kit available. We do not recommend using the spring loaded lock for general use as the kit is new and we do not know how the springs will stand up to extended hard use. Also the spring lock will make emergency bailout from the helmet more difficult as the lock will have to be held back to open the clamp.

The clamp and lock system was part of the original design of the Air Hat and has worked reliably for 47 years. The incident above is serious but should not be taken as indicative of a significant risk factor in using the Air Hat.

Recommendations:

Always check the drag on the clamps and locks during pre-dive. Adjust as necessary. Routinely check the condition of the retaining bolts, nuts, and Nylon washers. Replace the Nylon washers if any sign of wear or compression is evident.

The safety notices below are the result of situations DESCO has found when Air Hats have been returned to us for repair or inspection.

1. Air Diffuser/Muffler and Lambswool.
The Air Diffuser/Muffler in the DESCO Air Hat comes packed with Lambswool to reduce the noise created by the airflow through the system. NEVER substitute a different material for Lambswool in the Air Diffuser/Muffler. Air Hats have come back to DESCO for repair with steelwool, cotton, fabric, brass pot scrubbers, and other materials in the Air Diffuser/Muffler. Lambswool is resistant to moisture, oil, and compacting, and it allows good air flow. It also will trap dirt and contaminates from the compressor and hose. Checking the condition of the Lambswool should be a routine part of maintenance of your Air Hat. Any unusual or excessive contamination of the Lambswool can indicate a problem in the air supply system. Oil or grease, excessive moisture, dirt, or rubber particles in any significant amount in the Lambswool should be investigated. Lambswool is available at stores which sell health and beauty supplies (i.e. drug stores, grocery stores, department stores).

2. Teflon® Tape and air delivery.
Never use Teflon® tape on any part of the primary or secondary air delivery system. Strands of Teflon® tape may enter the air delivery system and clog the air diffuser or air control valve resulting in the loss of breathing air. DESCO recommends using a good quality pipe joint compound available at hardware stores and home centers.

3. Suit Inflator Whips and air delivery.
The DESCO Air Hat does not have a provision for connecting a suit inflation hose from the helmet to the suit. It has been noted that some divers have installed additional plumbing on the Air Hat inlet to equip it with a inflator whip hose. This practice presents the possibility of snagging the helmet or breaking off the additional plumbing and/or the air inlet elbow. DESCO advises against using the primary air source for anything other than diver life support. A secondary source of air should be used for suit inflation, such as a pony bottle. Never modify the air delivery connections on the Air Hat. The air inlet elbow is designed for the lower Non-Return Valve to accept the umbilical primary air line. The upper Non-Return Valve is designed to accept the same standard hose fitting as the lower, but it will also accept a SCUBA whip from a Bailout Bottle. Non-Return Valves which are made to accept a SCUBA Whip have a "B" stamped next to the inlet.

4. Removal of Double Exhaust Valve Center Section.
DESCO has received Air Hats for repair where the center section of the Double Exhaust Valve have been removed. The reason for this action is unclear. Removal of the center section WILL NOT increase the flow rate through the exhaust. DESCO has tested the exhaust and the flow rate is the same either way. What removal of the center section does do is increase the risk of leak back into the Air Hat exposing the diver to contaminated water. The Double Exhaust Valve should be checked and maintained on a regular basis. Dirt, hair, and old flapper disks can effect the performance of the Double Exhaust Valve.

5. Non-Factory Modifications to the Air Hat.
Making modifications to the Air Hat not authorized by DESCO could result in the failure of the Air Hat to perform safely and effectively. Do not drill holes through the Air Hat to mount lights, cameras, or other equipment. Never attempt to powder coat a Air Hat as the solder will melt out before the coating reaches its necessary melting temperature. DESCO is willing to make reasonable modifications to Air Hats to address individual divers needs, as long as it does not compromise diver safety.

Routine Maintenance

Performing regular inspection and maintenance on your helmet and related equipment will significantly increase safety and reliability. Implementing a preventative maintenance program will lower costly down time and potential safety risks. Using well maintained equipment you can operate more efficiently, at lower cost.

All components of the diving outfit work together to provide the diver with a safe environment. Each part from the compressor to the dry suit have to perform correctly in order for the diver to complete a dive in a timely and safe manner. Servicing each part regularly will reduce the possibility of breakdown on the jobsite, where more than just time could be lost.

Replica/ Reproduction Helmets

With the increase in interest in collecting and using old diving equipment the possibility of someone attempting to use a replica/ reproduction helmet by accident or intentionally also increases. These helmets were never intended for actual use. NEVER attempt to use any diving helmet without thoroughly inspecting and testing it before entering the water. ALWAYS make sure you have the proper training, equipment, and safeguards in place before you dive.

Safety Issue Gallery

We have gathered together photos from DESCO Air Hats we have repaired through the years. Some of the issues depicted are on helmet which were in prolonged storage. Some issues did not necessarily preclude using the helmet but could affect diver comfort thus impacting safety. Other issues were just plain NO NOs.

Cracked solder joints

The damaged joints pictured below are mostly due to the fitting being hit and the shell bending. A catastrophic failure is unlikely but a significant air/water leak most likely will result. Anytime a fitting on a helmet receives a hard blow the entire area should be carefully inspected. This same damage can be seen on classic helmets.

Cracked windows

The window on a air hat is not cheap and it is understandable that owners want to get the greatest possible use out of them. The window is made of 1/2"acrylic which is pretty tough stuff. We have seen windows with more line running through them than a stained glass church window. These disappear underwater but the underlying damage to the material is still there. Edge damage weakens the window and chips in the edges more so. I have seen one completely cracked through window so it can happen. Another issue is crazing inside the plastic. Tiny cracks centralized in various areas throughout the window. These are nearly impossible to photograph and you have to angle the window at a very sharp angle to see them. If your window has them toss it into the recycle bin.

Teflon® Tape in the air train

We hammer this one over and over. NO TEFLON TAPE IN THE AIR TRAIN. Still we have helmets coming in with the non-return valves wrapped in the stuff. Lose strands of the tape can get into the control valve or the lambswool and clog them up. Only use plumbers pipe thread compound to assemble components in the air delivery system. In the second photo Teflon tape was used to install the inside elbow instead of two part epoxy.

Part Damage

Through normal use, age, and occasional mishap parts get damaged. Some damage may just be inconvenient and other be dangerous.

Above valve stems are often bent because of the exposed position. Extenders can be broken when the stem is bent or the solder joint can fail from galvanic corrosion.

We're not sure how this occurred but it would render the second exhaust flapper useless.

The Non-return valve can be snapped off if it is struck hard or is in line with an extension from the elbow. The additional plumbing here added six inches off the back of the elbow. The owner wanted to add a bailout port on a single elbow equipped helmet and possibly a inflator whip.

Age and wear will eventually destroy parts on the helmet. Sometimes excessive pressure from over tightening screws will compress or crush the binding post bushings or Nylon washers in the clamp & lock assemblies.

Failure due to use, age, and wear

Regular and routine inspections are vital in keeping a helmet safe and ready. Inactivity can be as detrimental to a helmet as extensive daily use and sometime more.

Dirt & corrosion on the face of the exhaust valve sections will prevent a good sealing surface for the flapper. Dirty lambswool will restrict air flow. A very old flapper has begun to crack apart and has attached itself to the plunger in the exhaust valve top section.

The rubber disk face can rupture from air getting underneath it. The rubber disk face can detach from the Brass plate and stick to the adapter. A missing screw can affect the ability of the exhaust valve to function and if the second screw falls out, the loss of the top section.

Over time the neck ring gasket will dry out and begin to crumble.

Improper storage of a helmet can result in mold on the head liner or a spider taking up residence and raising a family in your non-return valve.

Creativity in the field

Often times divers will modify the helmets to suit their individual needs. Many times this works out, sometimes not so much. In allot of cases there will be reasons why DESCO can't sanction modifications. The design of the air hat was well thought out and updates and improvements made by DESCO have been extensively check and scrutinized before they became part of the standard design. Many changes were prompted by suggestions from divers and contractors who depend on the air hat. DESCO has taken a stand on some proposed features for reasons that are clear to us but perhaps not to those who proposed them. Two examples are a nose clearing device and a port for a inflator whip. The nose clearing device would require another hole to be drilled into the window. There are six holes in the window already and the tradeoff between the strength of the window and the convenience of the nose clearing device is not one we are prepared to make on our product. Another consideration is the significant additional cost which would come with adding the device. Making an attachment for a inflator whip would entail tapping into the breathing air supply. DESCO is against any intrusion into the breathing air supply by a secondary system. We believe better options for suit inflation are a dedicated line from the surface or a pony bottle.

That said, we still get in some interesting field mods. Light mounting seems to absorb much time and effort.

Our main objection to mounting brackets off the window screws is reusing the Brass screws. They will not take much strain and if they break you could have a serious leak. The third photo shows a tractor light mounted on two Brass window screws. This assembly could easily be broken off especially with that heavy light in the exposed position.

Another mounting method has been to drill holes into the snout. We have seen tractor lights bolted to the center of the snout with a hole completely through the snout.

Speaker & microphone epoxied into the helmet. When we got the helmet the speakers nearly fell out on their own. It could have been a problem had they come loose during a dive.

Field repairs

Another creative endeavor is shade tree repairs to the helmets. While we can understand an emergency repair to finish a job permanent correct repairs should be made as soon as possible.

Wire and tape are popular repair media.

Proper reassembly of the helmet after an inspection or repair is vital to the components operating as intended. Here you have a simple error of the Nylon washer being installed in the wrong place. In this location it serves no function. In the correct position it is the spacer and friction plate for the clamp.

Miscellaneous

Some of the photos not used above.

A collapsed loop. Not a very trustworthy attachment for your safety rope. This casting could easily fail under stress.

Shell dents are not uncommon in air hats. Metal helmets get less gentle treatment than their fiberglass brethren. Generally not a safety issue unless the Copper is punctured or the dent is at or adjacent to a soldered fitting.

While not a safety concern in and of itself. Proper shipping and transport are essential to preventing damage that might impact safety.

Last words on Safety

DESCO works hard to provide safe, reliable, and cost effective equipment. Once it leaves the factory we have little to no control in its use or maintenance. It is up to each diver to make sure the helmet is capable and ready to deliver the performance we promise. Small things like a missing screw, a piece of debris in the exhaust, or a mass of extra plumbing can cause at least an inconvenience and at most a death.

DESCO continues to make our products as safe and reliable as possible. Ultimately the responsibility for your safety rests with you. Proper training, preparation, and execution of a diving operation falls to the diver and his support crew. DESCO appreciates our customers and wants them around for a long, long time. Dive safe.