The encoding guides may be to technical.

BasharOfTheAges · Post by **BasharOfTheAges** » Fri Jan 26, 2007 10:20 pm

That guide doesn't just jump into technical things. It spends a long time explaining the aspects of simple concepts and expands upon them to teach the reader a great deal about exactly why things are done the way they're done and what helps with what. I'm not seeing any evidence on your part to something that is rushed into and explained in too technical of a manner. All I've seen is you skipping or not reading sections that explain other sections. Give some examples of terminology that is over complicated and is not explained elsewhere, and there'll be some merit to what you're saying.

trythil · Post by **trythil** » Fri Jan 26, 2007 11:28 pm

James Sharp wrote: For example: The mark three fire service pump is a centrifical pump it pumps 300gpm at 200psi... the mark 3 pump is very prone cavitation and as such measures should be taken to prevent cavitation at anytime before running the pump.

Now can you tell me what you have gotten from that? Probably nothing because it is very technical.

Sure:

- There are many pumps that bear the "Mark III" moniker, but given your profession, the Wildfire Mark-3 fire service pump seems like the most likely candidate.

The official specifications for the Wildfire (Wajax) Mark-3 don't match what you say -- in particular, the cut sheet for the pump lists it as delivering a maximum of 52 US GPM (43.3 IMP GPM) at 200 psi. However, the cut sheet is outdated, and it's entirely possible that you're talking about a different Mark-3, so clarifications are welcome.

The Flowserve Corporation also manufactures a pump designated as "Mark-3", but it doesn't look like that pump satisfies the criteria you gave.

- The Mark-3 fire service pump is prone to cavitation, i.e. cavities have a tendency to form in the liquid being pumped. I'm not sure which pump you're talking about, so I cannot deduce or find the reasons for its cavitation tendency at this time.

- Cavitation has a number of basic root causes, among them:
- fluid vaporization due to low pressure and/or high temperature
- turbulence in the fluid flow caused by corrosion or obstructions in the piping
- the tip of the impeller passing too close to the pump cutwater, increasing the fluid velocity, leading to vaporization

and others that I'm still looking up.

- Cavitation is particularly dangerous in pumps because:
- Cavitation causes excessive vibration, which can cause the seal and/or bearings of the pump to fail.
- Bubbles formed in the liquid by cavitation can implode, giving rise to extremely high-velocity microjets of fluid. The force of such implosions generally act on the entire surface of the bubble. However, if the bubble is resting on a surface (e.g. pump impeller or volute), the portion of the bubble surface in contact with the pump surface cannot implode, causing the microjet to bang against the pump surface, which contributes to erosion of pump parts, e.g. formation of pits in the pump impeller and diffuser.
- Cavitation is also known to unbalance the impeller, which, if left unchecked, can completely wreck the pump.
- Bubble implosion can destroy protective coatings on the metallic pump surfaces, thus leading to corrosion.

James Sharp · Post by **James Sharp** » Sat Jan 27, 2007 3:01 am

trythil wrote:
James Sharp wrote: For example: The mark three fire service pump is a centrifical pump it pumps 300gpm at 200psi... the mark 3 pump is very prone cavitation and as such measures should be taken to prevent cavitation at anytime before running the pump.

Now can you tell me what you have gotten from that? Probably nothing because it is very technical.
Sure:

- There are many pumps that bear the "Mark III" moniker, but given your profession, the Wildfire Mark-3 fire service pump seems like the most likely candidate.

The official specifications for the Wildfire (Wajax) Mark-3 don't match what you say -- in particular, the cut sheet for the pump lists it as delivering a maximum of 52 US GPM (43.3 IMP GPM) at 200 psi. However, the cut sheet is outdated, and it's entirely possible that you're talking about a different Mark-3, so clarifications are welcome.

The Flowserve Corporation also manufactures a pump designated as "Mark-3", but it doesn't look like that pump satisfies the criteria you gave.

- The Mark-3 fire service pump is prone to cavitation, i.e. cavities have a tendency to form in the liquid being pumped. I'm not sure which pump you're talking about, so I cannot deduce or find the reasons for its cavitation tendency at this time.

- Cavitation has a number of basic root causes, among them:
- fluid vaporization due to low pressure and/or high temperature
- turbulence in the fluid flow caused by corrosion or obstructions in the piping
- the tip of the impeller passing too close to the pump cutwater, increasing the fluid velocity, leading to vaporization

and others that I'm still looking up.

- Cavitation is particularly dangerous in pumps because:
- Cavitation causes excessive vibration, which can cause the seal and/or bearings of the pump to fail.
- Bubbles formed in the liquid by cavitation can implode, giving rise to extremely high-velocity microjets of fluid. The force of such implosions generally act on the entire surface of the bubble. However, if the bubble is resting on a surface (e.g. pump impeller or volute), the portion of the bubble surface in contact with the pump surface cannot implode, causing the microjet to bang against the pump surface, which contributes to erosion of pump parts, e.g. formation of pits in the pump impeller and diffuser.
- Cavitation is also known to unbalance the impeller, which, if left unchecked, can completely wreck the pump.
- Bubble implosion can destroy protective coatings on the metallic pump surfaces, thus leading to corrosion.

you know thats kinda the point i was getting at.

I just spouted a buncha technical stuff.. of course it is not by the book... but still technical.

just so you know the most common cause of cavitation in the wildland mark 3 pump is bubble implosion.

It is caused when the operator shuts off all nozzles running from the pump. Thus the water has nowhere to go and it is just being spun around the outer part of the pump housing.

As a result the water begins to boil and the bubbles implode... they then put small dents in the fins and outer casing of the pump housing.

This is called implosion.

You see the thing is i didnt have to look any of my info up.. and that is exactly my point.

you had to look up that info.. you could not just know the ins and outs of the pump by a overly technical outline..

Your post only further proved the point i was trying to make.. thanks.

But lets stop this now before it gets any more off track. i have heard the general opinions of others on this subject and they dont seem to agree with me..

Obviously that only points to this being a personal problem that only i am experiencing. as such my opinion is considered wrong.

So now that i know the guides are not overly technical because the majority of posts had been against my opinion..

Im good.. mods can shut this sucker down if they like... before it degrades into the actual flow rate of the mark 3 pump (glad someone didnt call me on that one)

trythil · Post by **trythil** » Sat Jan 27, 2007 3:56 am

James Sharp wrote: You see the thing is i didnt have to look any of my info up.. and that is exactly my point.

What's the point? Do you expect to know everything relevant about a subject while doing nothing?

Of course I had to look stuff up. That's the idea. If you don't understand a subject, you pick out context and keywords, and you do your homework.

dokool · Post by **dokool** » Sat Jan 27, 2007 5:59 am

trythil wrote:If you don't understand a subject, you pick out context and keywords, and you do your homework.

JaddziaDax · Post by **JaddziaDax** » Sat Jan 27, 2007 7:15 am

actually i found the XVID guide to be "fill in the blanks"

>.>

Zarxrax · Post by **Zarxrax** » Sat Jan 27, 2007 12:01 pm

JaddziaDax wrote:actually i found the XVID guide to be "fill in the blanks"

>.>

How in the world? The xvid guide is one of the most completely thorough guides and holds your hand every step of the way. What does it possibly leave out?

JaddziaDax · Post by **JaddziaDax** » Sat Jan 27, 2007 1:34 pm

Zarxrax wrote:
JaddziaDax wrote:actually i found the XVID guide to be "fill in the blanks"

>.>
How in the world? The xvid guide is one of the most completely thorough guides and holds your hand every step of the way. What does it possibly leave out?

thats NOT what i meant... i meant follow the screencaps, and fill in the blanks on MY Vdub... its a wonderful guide, i thought it was simple... you can just coppy the screencaps, and that will get the job done O.o

Zarxrax · Post by **Zarxrax** » Sat Jan 27, 2007 2:23 pm

Ah, I see

James Sharp · Post by **James Sharp** » Sat Jan 27, 2007 5:35 pm

well.. im gonna have to resay it..

Im wrong. I made a statement. and it was terribly wrong. this has been proven time and time again.

Now to keep from further pissing off the ENTIRE community please close this thread so i dont have to suffer the indignity of everyone saying how easy the guides make things for them.

When i see about seven of the top names on this site all disagreeing with me i can take a hint and know when i have made a mistake.

[MOD 403: locked at thread starter's request]