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<p>The Perkins A3.152 engines I worked on had a CAV pump and used an
injector set at 1750 to 1800 PSI cracking pressure. If the pump
was a little weak we would drop the cracking pressure down to
1600-1650. It would help starting if the tractor had a good
battery. It advanced the timing of the injection some. By
lowering the injector cracking pressure, we could make a weak
head/rotor combo last another 200-250 hours. <br>
Cecil<br>
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<div class="moz-cite-prefix">On 2/9/2020 12:09 PM, James Peck wrote:<br>
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<pre class="moz-quote-pre" wrap="">You were correct Cecil. I have included the Parker fittings brochure again. Some of the steel fittings are rated to 2800 psi. Any tubing or other component nneds to have a working pressure rating that excedds the injection pressure. All components in the high pressure injection side need to be rated above the peak injection pressure. We have not been furnished the peak injection pressure. Without knowing the actual injection pressure, it is anybody's guess what pressure rating we need to selct for. Pressure rating of tubing ddepends on its wall thickness, diameter, matrial, and method of manufacture. Parker does not sell the tubing. It comes from other venders. With tubing I believe you select it by OD and pressure rating.
Does John's friend know the injection pressure on a Standard Ricardo 23C engine?
Buying good shape injector tubes may not solve the problem if they have to be bent to clear the glow plugs. Is that the case with the ebay sourced tubes?
Not all fittings seal by drawing in a ferrule to the tubing.
<a class="moz-txt-link-freetext" href="https://www.iso.org/standard/70228.html">https://www.iso.org/standard/70228.html</a> ISO 8535-1:2016
Diesel engines — Steel tubes for high-pressure fuel injection pipes — Part 1: Requirements for seamless cold-drawn single-wall tubes
The standard may be more stringent than the OEM tube and fittings.
Even more reason to go with the injector repair shop.
Thomas Martin AT List Member (<a class="moz-txt-link-abbreviated" href="mailto:tmartin@xtra.co.nz">tmartin@xtra.co.nz</a>); Hi Cecil, I was actually responding to James' post that referred to a reinforced nylon Parker product. There is no real substitute for injector pipes other than injector pipe "tube". Heavy wall as it is, one can still feel the pulse, by holding a pipe between fingers...
Cecil Bearden AT List member, Oklahoma farmer, and Professional Engineer (<a class="moz-txt-link-abbreviated" href="mailto:crbearden@copper.net">crbearden@copper.net</a>); At the time I wrote this I was thinking hydraulic steel tubing. Hydraulic tubing fittings have a ferrule that clamps down on the tubing when tightened the first time. Most diesel tubing has the ferrule brazed on to the tubing.
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