hi folks,

I have to design a pipe carrying 4000 psi having an circular opening
into another pipe covering/surrounding the internal pipe..

i referred Machine Design data book by K. Lingaiah and got this
formula

tangential stress : óè = a + b/r2

radial stress : ór = a - b/r2

where,

a = ( pi * di^2 - po * do^2) / ( do^2 -
di^2)

b = { di^2 * do^2( pi - po) }/
{ 4r^2( do^2 - di^2)}

pi = internal pressure
po = external pr.
di = inner dia
do = external dia.
r = any radial distance

now, if external and internal pressure are equal.. tangential and
radial stress will be equal to -ve pressure value..

is that ok? .. that i can have any inner dia and thickness (if
material's permissible yield strength is more than applied pr.)

pls help me with that..

regards,
Pranav

On Jan 6, 2:19*pm, hard stuff
wrote:
hi folks,

I have to design a pipe carrying 4000 psi having an circular opening
into another pipe covering/surrounding *the internal pipe..

i referred Machine Design data book by K. Lingaiah and got this
formula

tangential stress : óè *= a + b/r2

radial stress : ór *= *a - b/r2

* * * * * * * * * * * * * where,

* * * * * * * * * * * * * * a = ( pi * di^2 - po * do^2) / ( do^2 -
di^2)

* * * * * * * * * * * * * * b = { di^2 * do^2( pi - po) }/
{ 4r^2( do^2 - di^2)}

* * * * * * * * * * * * * * pi = internal pressure
* * * * * * * * * * * * * * po = external pr..
* * * * * * * * * * * * * * di = inner dia
* * * * * * * * * * * * * * do = external dia.
* * * * * * * * * * * * * * r = any radial distance

now, if external and internal pressure are equal.. tangential and
radial stress will be equal to -ve pressure value..

is that ok? .. that i can have any inner dia and thickness *(if
material's permissible yield strength is more than applied pr.)

pls help me with that..

regards,
Pranav

i want to

If you've really got the same pressure inside and out it's under hydrostatic
pressure; so yes, it can be any size, shape, or thickness that you want. It
will deform elastically, it won't deform plastically.