O-lets Requirments

[novice123]

In refinery , practically under what conditions do we require each O-lets ( Weldolets , threadolets, Elbolets, sockolets, latrolets)...?

[novice123]

Any idea?

[ashfaqanwer]

Scockolets - are used for taking branch connection in smaller sizes up to 1-1/2" for piping upto 600# rating (see note 1)
Weldolets - are used for taking branch connection in sizes from 1/2" to like 6" or 8" for piping above 600# pressure rating (see note 1)
Note 1: The difference between sockolet and weldolet is towards branch end connection which is socket welded in sockolet and butt welded in weldolet. Later having more strength.
Threadolets - are used in screwed / threaded piping having branch side end connection of threaded joint. They are only used when all the piping is having threaded connections having low pressure conditions
Elbolets - are used to take tapping from elbows for inserting thermowells, pressure gauges, venturi or taking a branch connection. These are used only under some specific requirements.
Laterolets - are used where an odd entry into the running pipe is required to be given in order to have smooth flow into the running pipe with minimum flow interruptions.

[novice123]

Thank you very much Sir for your valuable response.

In case of latrolets , Is there any specific chemicals which require minimum flow interruptions.???

[arcpro]

Latrolets are used where minimum resistance to flow is required.

[novice123]

Is there any specific chemicals which require minimum flow interruptions.???

[ashfaqanwer]

You are welcome novice.
Chemicals not particularly. It depends on the flow conditions, in order to induce lesser turbulence, lesser delta P. Need for latrolet is always a call by process engineer.

[siva2161]

Thanks you boss

[novice123]

1) What is the criteria for using reinforcing Pad for stub-ins . when we will use reinforcing pad for stub-in and when we will not?

Regards

[arcpro]

There is no short cut to assess the requirement of reinforcing pad else performing calculations as described in relevant design code.