Valve Back Seat Test

[Gopi Perumal]

Dear all,

Anybody can explain what is mean by Backseat test in Valve Testing? (API 598)

Thanks,
P Gopi

[n.gupta]

Dear Gopi,
In Gate and globe valves there is a backseat provision on bonnet below
stuffing box.
During line pressure if gland is leaking,you have to replace the packings.By
putting valve at fully open condition (backseat position).
To check the backseat you have to see leakage through gland.

Thanks
n.gupta

Dear all,

Thanks,
P Gopi

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[Muthusrinivasan Muthuselvam]

Dear Mr.Gopi..

 

The contact area between the stem & gland packing is known as  back seat  area. This back seat testing is applicable for gate & globe valve. During the testing the gland bolts should be in free condition so that no external force is applied on the gasket in the gland area.

 

br,

msms

On Mon, Jan 23, 2012 at 10:59 AM, Muthusrinivasan Muthuselvam <msm...@gmail.com> wrote:

Dear Mr.Gopi..

 

The contact area between the stem & gland packing is known as  back seat  area. This back seat testing is applicable for gate & globe valve. During the testing the bonnet bonnet should be in free condition so that no external force is applied on the gasket in the gland area.

 

br,

msms

[MM]

Dear Gopi,

Valve back seat tests are done in Gate and globe valves

It's done by opening the valve to the fullest and loosening the packing
gland and pressurizing the shell.

It's done at 1.1 times the maximum allowable pressure at 38 °C (100 °F)

Cheers
MM

-----Original Message-----
From: material...@googlegroups.com
[mailto:material...@googlegroups.com] On Behalf Of Gopi Perumal
Sent: Saturday, January 21, 2012 8:01 AM
To: material...@googlegroups.com
Subject: [MW:13531] Valve Back Seat Test

Dear all,

Thanks,
P Gopi

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[vijaya chandran]

http://www.swivalve.com/pdf/SWI_Procedure_API.pdf

gothru

vj

On Sat, Jan 21, 2012 at 9:31 AM, Gopi Perumal <parini...@gmail.com> wrote:

[Vinod Jotwani]

Dear Mr Gopi,

Some of the valves are provided with backseat features. The backseat features enables the maintenance crew to replace the gland packing even when the system is under pressure. i.e. the valve is opened fully to 100 %  and the conical shape of the stem touches tightly against seat construction ( back seat ) in the valve body which seals off the fluid passing to gland packing area. Thus one can replace gland packing on line.

Vinod

---

From: Gopi Perumal <parini...@gmail.com>
To: material...@googlegroups.com
Sent: Saturday, January 21, 2012 12:01 PM

Subject: [MW:13531] Valve Back Seat Test

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[Vivek Joshi]

Hi,

Back seat is the test carried out to check tightness of "Back Seat" of valve.

As we know, pressure test is carried out to check integrity of the valve body, back seat test ensures that valve shall not leak when valve is fully open and pickings are untightened when valve is fully pressurized. Generally we mention in valve data sheet that , valve packing shall be replaceable under full pressure. This test is linked with that note. During test valve is fully opened (disc rest on back seat) & leakage is checked. Please cl.6.2.1 of API 598. This test can be combined with shell test.

Honestly speaking, nobody would dare to replace packing when valve is fully pressured in routine work.

 

Regards,

Vivek

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[santhosh kumar]

Dear Gobi

Backseat will be done for gate and globe valve...That is nothing but
the handle will be opened fully and this test main purpose of stem
seat.
The test pressure is 1.1 times of MOP.

Regards

Santhosh

[rawat...@gmail.com]

What is difference between seat test and closure test.
What is the required position of gate during back seat test.
Regards

Rawat

[kingslygeo vargheese]

Good Morning,

seat test and closure test  - Same.

Back seat test - The Gate / Globe valve in full open condition.

The  Stem ( Back seat ) lock the stem bush in the bonnet to avoid leakage.

Shell test - Partial open -  1.5 times design pr 

Back Seat - Full Open    - 1.1 times design pr  

Seat Test - Full close  -     1.1 times design pr 

Best Regards

Kingsly Geo

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