GGDT/HGDT Request Thread

[MrCrowley]

So this is a topic where you may request GGDT/HGDT outputs assuming your own computer is unable to run them. To make a request, you will be required to understand how to use GGDT/HGDT. This thread isn't for people who are too lazy to learn how to use the programs.

Guidelines:

*You must provide all relevant input parameters for the GGDT/HGDT simulation. A list of input parameters can be found HERE. Obviously parameters like "Hamr Mass" are not required when modelling valves that don't have a hammer.
*If you are unsure of what values to put for some of the valve parameters (such as dwell time, flow coefficient, etc), provide as much information as possible about the valve and the person running the simulation should be able to estimate a value.
*We are not work horses so if you wish to request more than one simulation (e.g. change in pressure, chamber volume) for a particular design, please request all simulations at the same time. Saves us time and effort.
*If no one accepts your request, wait a few days before requesting again.

If anyone has any suggestions to improve this thread, just comment below.

Any topics asking things like what size chamber/barrel they should have on their cannon or how powerful their cannon may be, will be merged here for someone to compute an output for them.

[Lockednloaded]

Does anyone know the valve parameters for a pressure washer with 8gpm flow, or 30L/min?

[Technician1002]

I'll take the first request even though it is not GGDT related.

The answer is the valve must be considerably larger than the spray orifice. The spray orifice is the flow restriction and the pressure dripping device. The valve when open should provide minimal pressure drop to the flow.

With that in mind, any valve that can withstand the pressure and is able to handle the flow will work. Use from a 3/8 inch orifice or larger and it should work fine.

8 gallon/minute is on the high side of the range of pressure washers. How many HP is the engine on that one?

The basics is covered in this PDF.. http://media.wattswater.com/pressuredro ... sizing.pdf

[Lockednloaded]

*If you are unsure of what values to put for some of the valve parameters (such as dwell time, flow coefficient, etc), provide as much information as possible about the valve and the person running the simulation should be able to estimate a value.

Sorry, I was unclear. I want information that would be plugged into GGDT about the valve on the handle

[Technician1002]

Sorry. Do you have more information on the valve? Orifice size eta?

[MrCrowley]

I'll take the first request even though it is not GGDT related.

I guess it would make sense if we allowed valve requests (like what Lockednloaded asked) here too.

[nathanhd123]

I have been playing around on GGDT and I am a bit stuck on the valve data. What data should I put in for a 3/4" QEV?

[mattyzip77]

I am not sure, Im new to the whole ggdt thing as well, I would guess generic??

[nathanhd123]

Once you put generic in how do you know what dwell time, open time, seat diameter, dead volume and flow coef is?

[jackssmirkingrevenge]

Ideally to get a good estimate you should take it apart and take some measurements, and weigh the piston/diaphragm.

GGDT's models are only as good as the accuracy of the data you put in.

[nathanhd123]

How do you take it apart as I cannot see any screws. Can you give me some average data for a 3/4" QEV?

[mattyzip77]

If there are no screws, I would imagine you put a pair of pumps, aka channel locks, or a wrench on either end, and twist in opposite directions

[POLAND_SPUD]

How do you take it apart as I cannot see any screws. Can you give me some average data for a 3/4" QEV?

The cutaway view shows the threads between the main valve body and the cap on the pilot side... don't worry you can open that as the pilot port is not ideally round

[MrCrowley]

@nathanhd123

Topic merged. We now have an official GGDT request thread, please post all future GGDT enquiries here.

[nathanhd123]

I have just found this page on my QEV. Can anyone make sense of it? I am trying to get some data to put into GGDT as I do not have a spanner big enough to open my QEV. http://www.airlines-pneumatics.co.uk/we ... 070139.pdf

This is my QEV. Mine is the 3/4". http://www.airlines-pneumatics.co.uk/we ... de=S070139