Weldolet/Threadolet Trimming

[Quality2479]

Hi,

I have two questions regarding Weldolet which are mentioned below-

1. I have a Weldolet of size designation/marking as 36"-2" x 3/4" 3000# - which means we can use this Weldolet for Run pipe sizes ranging from Dia 2" to 36" with an outlet size of 3/4". This particular Weldolet is not perfectly fitting up with an Run Pipe of Dia 4". Whether we can trim the weldolet and can suit to the size of the run pipe in order to make a good fit-up to weld ?

If the answer is YES, If we trim the weldolet, whether there will be an affect on the design parameters & whether is it acceptable as per ASME B31.3?


2. While going through one of the Manufacturer data sheet of Weldolet, I observed that the dimension from Center of run pipe to the face of Weldolet is been mentioned. Whether is it important to maintain that dimension because I couldn't find it in ASME B31.3 Since these are for process piping. Please Refer attachment (Dimension L1).

Thanks in advance for valuable answers/replies.

 

[pvrerate]

I would suggest that you contact the WOL manufacturer and ask them your questions. They are in the best position to give you an answer.

 

[chicopee]

I would not want to reshape the weldolet as you may forfeit its integrity. PVrerate suggestion is a good one.

 

[rneill]

In Canada, you would invalidate the CRN on the fitting and thus render it unfit for service if you modified it in this way.

 

[TD2K]

That seems like a wide range for a single weldolet to fit. I looked at Bonny Forge's catalog and for a 3000#, you can get a weldolet spanning 14" through 36", a long way from 2" through 36".

 

[rneill]

There are a wide range of manufacturers out there and design / dimensions of weldolets is up to the manufacturer. MSS SP-97 provides design criteria and does not provide dimensions. Consequently, you are trusting that the manufacturer knows what they are doing and that the fitting really is "fit for purpose" for the range of 2" thru 36" but buyer beware.

2" thru 36" seems like a large range and it would almost inevitably be a poor fit at the ends of the range (very small sizes and very large sizes. All those pipes have a different curvature and you can't cheat physics, there is no way that you can be perfectly fitting on all these sizes, The best the manufacturer can possibly do is pick some intermediate curvature and then the fitting will bottom out in the crotch for small diameters and it will sit on the skirt with a crotch gap on large sizes. No way around this.

Per MSS SP-97, the maximum permissible gap, either the crotch gap or skirt gap, for a Weldolet is 1/16". If you have a gap larger than this then the manufacturer has specified too large a size range and is not in compliance with MSS SP-97. If this were the case, I would take that manufacturer off my "Approved Manufacturers List" and purchase from a manufacturer who was designing in accordance with the standard.

 

[Kiwi2671]

Quality2479,
There is no problem with using the weldolet as noted.
And IMHO there is no problem with trimming to suit.
Bonney Forge catalogue P 38/39/40 (see attached)states that weldolets are made to suit a multitude of run pipe sizes (eg. 1 1/2" to 36") and all weldolets are manufactured in accordance with MSS-SP-97-2001 (maximum 1/16" gap at crotch or skirt)
36" will have a gap at the crotch and 1 1/2" will have a gap at the skirt.
Bonney Forge state this gap is negligible when welding.
The body of the weldolet has to be a certain schedule (thickness) but they have a tapered bevel so if you grind 1/16" off the bevel in the crotch or skirt you have not altered the schedule of the fitting and IMHO you have not affected the integrity of the fitting.
Regards,
Kiwi

 

[rneill]

Quality2479,

I'm curious, what is the approximate gap at the skirt of the fitting? Is it within the 1/16" permitted by MSS SP-97?