Pat-3500

Hello everyone. (I also posted this in the 3rd gen forum by mistake- sorry). I got my new 2002 3500 24V ISB 6-spd 2 months ago and have 18000 KM on it already. I take this thing to work everyday on oilfield projects - great truck. My dealer can't find a positive airflow shutoff device, this is a required safety device for diesels operating near an oil and gas facility. Do any of you have any suggestions as to manufacturer and how to install this thing? Thanks.

Lil Dog

My buddy just had one installed on his Dmax a month ago. About $1800 Canadian for the kit installed, has a speed switch (electronic RPM setting) and the shutoff valve is electric. It fits into the intercooler lines feeding the engine. When activated the valve is closed with the electric solenoid and when open is full flow.

I will have to contact him about who actually manufactures it, then maybe a dealer your way can hook you up.

We went to a truck outfitting shop for large trucks, pickers, winch tractors etc. They knew exactly what we needed. If I want to use this truck I will also have to get one installed.

J-eh

Shovelhead

Sounds kinda like an exhaust brake in the intake tract.

admin

What purpose does having this device serve? I'm sure it's for safety reasons, but how exactly does it provide that safety? What does it prevent?

Shovelhead

It would prevent a run away engine if you encountered a fuel rich air environment.(I imagine that could be found rather easily in an oil/gas field)

admin

Wow. Cool. I didn't realize that something like that could even happen.

Shovelhead

Diesels have no throttle valve in the intake tract.<br>No way to shut it down if it finds an &quot;alternate&quot; fuel souce.<br>It will &quot;run-away&quot; until it over-revs and grenades.

phox_mulder

The &quot;run away&quot; was also talked about in the shutting off while refueling thread.<br>The truck gets a whiff of the gasser next to you refueling and runs away.<br><br>Kinda figured out what it was, this helps more.<br><br><br>phox

DarrellB

I've only heard of it happening once or twice to trucks while refueling but it's always a good idea if your refueling next to gas pumps to shut down the truck. <br><br>Shovelhead is right it will rev till it blows. provided there is enough vapor in the air to keep it reving that long.<br><br>The guys running in the new ATPA pulling class have to have on of these as well. And it's basiclly the same thing as an exhaust brake but on the intake side.<br><br>Be Careful out there.<br><br>Darrell

Lil Dog

I should have specified that its called a Positive Air Shutoff system.<br><br>As you all illuded to, its to keep someone for catching Cummins parts in the eye... <br><br>Most if not all Oil and Gas companies won't let you on site without at least a manual setup. But now the standard system is the electronic system. They set the overspeed setting to just over red-line and its live all the time. There is also a manual E-switch just incase you need it.<br><br>The valve is not like an exhaust brake, but more like a gate valve on a swing, there is no impedence of flow.<br><br>FYI...J-eh

Nigel

Here at the dealer we have been using Positive Air Shutoff Valves from Roda Deaco Valve. Very easy to install and they have 3 model to choose from(manual, electric, and manual electric combo). Call them at 1-780-465-4429 or on the web at www.rodadeaco.com 8)

Scotty

[quote author=Lil Dog link=board=4;threadid=5565;start=0#48882 date=1033792647]<br>I should have specified that its called a Positive Air Shutoff system.<br><br>As you all illuded to, its to keep someone for catching Cummins parts in the eye... <br><br>Most if not all Oil and Gas companies won't let you on site without at least a manual setup. But now the standard system is the electronic system. They set the overspeed setting to just over red-line and its live all the time. There is also a manual E-switch just incase you need it.<br><br>The valve is not like an exhaust brake, but more like a gate valve on a swing, there is no impedence of flow.<br><br>FYI...J-eh<br>[/quote]<br><br>J, I think Spanky had to put one of those on all his trucks just recently.

Pat-3500

Thank's Nigel for the contact and web link. Just sent them a msg, let you know what happens.

mariner

Hi J,<br><br>These things have been around for years on both stationary and marine diesels. Also, Detroit Diesel use something similar to what you are talking about in their 6V71 and 8V71 engines. These are connected (installed in) to the intake air system. They can be electrically (from a speed switch) operated, mechanically operated (from remote pull station) or locally operated for manual shut down. Once operated these usually need to be manually reset.<br><br>There are various types - some spring operated, some using a compressed air actuator and then there are the the ones that are spring loaded but electrical solenoid vales actuate the operation by moving a stop pin to allow valve to work.<br><br>I have seen two types - a guillotine valve and a swing valve. Both operate to completely shut of the air supply - no breathing no working. Work well, very positive and quick.<br><br>The operating system can vary but they all essentially do the same job. Try your local Detroit Diesel dealer - they might just be able to help. I think that all the Greyhound buses (all diesel buses) have these so that the engine cannot run away speedwise, in the event of a governor failure. The manual emergency stop in the drivers cab is used to activate this mechanism. To start the engine, the driver had to reset a spring loaded flap valve before the engine would fire up (no air as it was shut). <br> <br>As I understand it, our engines only regulate (through the governor) fuel delivery. They do not actually shut down on an overspeed surge by actually shutting down the engine. Instead the is reduced to lower power output (computer programming). Engine would still run but at a reduced output until the code is cleared by the dealer (reflashing memory?).<br><br><br>Hope this helps.<br><br>Mariner

ftltmp

I work for a major truck manifacturing plant and have seen
a few of these, mainly on fire trucks. It is installed on the
intake side of the charge air cooler,it almost looks like a pac
brake ,and is used to shutdown the engine instead of the
switch to prevent an electrical spark possibly at the battery
,or the cutoff switch. I hope this helps.