Valves on Isometric Drawings

[thalon]

Does the orientation of a valve on an isometric tell the installer/fabricator which direction the valve handle is to be oriented (horizontal or vertical)?

Dimensions on an isometric. Are they ALWAYS taken as center of pipe, unless otherwise noted? Even if the dimension and pipe are in different iso planes?
The Dimension 1'-7 3/4" in my atachement... do you read this as from the center of the purple pipe, or from the weldolet (edge of pipe)?

Thanks for any input.
Kevin

 

[Zapster]

Yes
Yes
Yes
The dimension is from the center of the purple pipe.

 

[thalon]

The problem was the pipe fitter didn't read it that was and assumed the dimension was face of flange to backside of weldolet. This is despite haveing the complete drawing with fully dimensioned plan and elevation views showing the same dimension as face of flange to center of pipe. and of course it's 6" stainless, not just 2" carbon steel.

Further question on the drawing. The valve handle in the field can only be placed in the direction as shown on the isometric due to surrounding piping and structures. Would I have been better off showing the valve vertical and placing the dimension in question in the vertical plane?

In five years of piping drafting this is the first time this question has arose.

Thanks.
Kevin

 

[Zapster]

If you do not care the direction of the handle/operator and assume that the pipe fitter knows best, leave the handle/operator off the ISO. Otherwise, show the handle oriented in the direction you want. Do not show the handle oriented in the wrong direction, especially if there is an obstruction. You might find the pipe fitter taking some initiative making some other changes such that the handle/operator will fit where you drew it.

 

[gmax137]

Is there any harm in showing it correctly *and* including a note re: handle orientation? I'm sure I've seen this done. (That's defense in depth, right, VPL?)

 

[Zapster]

I have only used/seen notes used when handle orientation is some angle outside of the the 3 standard planes, North/South, East/West, or Up/Down. IMO if it looks unclear, a note never hurts; however, a cluttered drawing with an unusual amount of notes does not promote clarity.

 

[gmax137]

Zapster said,

"a cluttered drawing with an unusual amount of notes does not promote clarity"

I agree with this 100% My suggestion that a note wouldn't hurt was based on the apparent difficulty in making the correct orientation clear, combined with the critical need to orient the handle correctly. Unnecessary notes are likely to cause unanticipated problems.

 

[LUDPEKA1]

I would have drawn it the same way you did. However if you think this could be an issue in the future, you could make the extension line from the weldolet a center line to try and clarify things.