How to calculate the pressure of cold-drawn seamless pipe

Cold-drawn seamless pipe is a kind of high-precision steel pipe formed by cold-drawn processing, because the inner wall and outer wall of the cold-drawn seamless pipe have no oxide layer, can withstand high pressure without leakage, high precision, high finish, cold bending without deformation, flaring, flattening without cracks, etc., so it is mainly used for the production of pneumatic or hydraulic components.
Mechanical structures or hydraulic equipment made of cold-drawn seamless pipes can greatly save machining hours, improve material utilization, and help improve product quality.

The pressure problem of cold-drawn seamless pipe is usually affected by the temperature of the working environment, internal fluid and production process. By measuring and calculating the wall thickness, outside diameter and tensile strength of the cold-drawn seamless pipe, the pressure level of the cold-drawn seamless pipe can be calculated by calculating the formula.

Pressure formula

1) Known cold-drawn seamless pipe outside diameter, wall thickness, pressure calculation method:
Tensile strength of steel pipe at different pressures = (wall thickness *2* Tensile strength of steel pipe material)/(outer diameter * coefficient)

2) The wall thickness calculation method of the outer diameter and pressure of the cold-drawn seamless pipe is known:
Wall thickness = (pressure * outer diameter * coefficient)/(2* tensile strength of cold-drawn seamless pipe material)

3) Cold drawn seamless pipe pressure coefficient expression method:
Pressure P7 Pressure P>17.5, coefficient S=4

For example:
DN=10MM, wall thickness 3mm, safety factor S=6, the tensile strength of No. 20 steel is 410MPa
The tensile strength of the cold-drawn seamless pipe is σ, the pressure is P, and the outer diameter of the pipe is D.
Cold drawn seamless pipe wall thickness δ= (P*D)/(2*σ/S); Where S is the safety factor;
Therefore, the pressure that the pipe can withstand P=(2*σ/S*δ)/D
410/6 = (2 * * 3)/(1 + 6)
=26.25MPa> Set 17.5
So the safety factor is S=4
Therefore, the pressure that the cold-drawn seamless pipe can withstand P=(2*σ/S*δ)/D
= (2 * 410/4 * 3)/(1 + 6)
= 39.375 MPa

4) Water pressure calculation formula
Bernoulli equation: p+ρgz+(1/2)*ρv^2=C
Where p, ρ and v are the pressure, density and velocity of the fluid respectively; z is the vertical height; g is the gravitational acceleration; C is constant

In summary, the bearing capacity of the steel pipe is closely related to the outside diameter and wall thickness, under the same wall thickness, the larger the outside diameter, the smaller the pressure value it can withstand, and under the same outside diameter, the thinner the wall thickness, the smaller the pressure value it can withstand.