# Bolted non-circular flat end with narrow-face gasket

## Values for calculation

$T$ $\mathrm{°C}$
$T_{test}$ $\mathrm{°C}$
$T_{assembly}$ $\mathrm{°C}$
$P$ $\mathrm{MPa}$
$P_{test}$ $\mathrm{MPa}$
$a'$ $\mathrm{mm}$
$b'$ $\mathrm{mm}$
$W$ $\mathrm{N}$
$c$ $\mathrm{mm}$
$n$
$t_B$ $\mathrm{mm}$
$R_{p0.2/T}$ $\mathrm{MPa}$
$R_{p0.2/T_{test}}$ $\mathrm{MPa}$
$R_{p0.2/T_{assembly}}$ $\mathrm{MPa}$
$R_{p1.0/T}$ $\mathrm{MPa}$
$R_{p1.0/T_{test}}$ $\mathrm{MPa}$
$R_{p1.0/T_{assembly}}$ $\mathrm{MPa}$
$R_{m/20}$ $\mathrm{MPa}$
$R_{m/T}$ $\mathrm{MPa}$
$R_{m/T_{test}}$ $\mathrm{MPa}$
$R_{m/T_{assembly}}$ $\mathrm{MPa}$

## Calculation

### Maximum allowed value of the nominal design stress for normal operating load cases

$\text{if }\ \text{type }$$\text{of }$$\text{material}= \text{Cast steels}$
$$f_d=\min\left(\cfrac{R_{p0.2/T}}{1.9}, \cfrac{R_{m/20}}{3}\right)$$
$\text{else if }\ \text{type }$$\text{of }$$\text{material}= \text{Austenitic steels}\wedge\text{min. }$$\text{elongation }$$\text{after }$$\text{fracture}\geq 35$$f_d=\max\left[\cfrac{R_{p1.0/T}}{1.5}, \min\left(\cfrac{R_{p1.0/T}}{1.2}, \cfrac{R_{m/T}}{3}\right)\right]$$\text{else if }\ \text{type }$$\text{of }$$\text{material}= \text{Austenitic steels}\wedge 30\le \text{min. }$$\text{elongation }$$\text{after }$$\text{fracture}< 35$
$$f_d=\cfrac{R_{p1.0/T}}{1.5}$$
$\text{else}$
$$f_d=\min\left(\cfrac{R_{p0.2/T}}{1.5}, \cfrac{R_{m/20}}{2.4}\right)$$

### Maximum allowed value of the nominal design stress for testing load cases

$\text{if }\ \text{type }$$\text{of }$$\text{material}= \text{Cast steels}$
$$f_{test}=\cfrac{R_{p0.2/T_{test}}}{1.33}$$
$\text{else if }\ \text{type }$$\text{of }$$\text{material}= \text{Austenitic steels}\wedge\text{min. }$$\text{elongation }$$\text{after }$$\text{fracture}\geq 35$$f_{test}=\max\left(\cfrac{R_{p1.0/T_{test}}}{1.05}, \cfrac{R_{m/T_{test}}}{2}\right)$$\text{else if }\ \text{type }$$\text{of }$$\text{material}= \text{Austenitic steels}\wedge 30\le \text{min. }$$\text{elongation }$$\text{after }$$\text{fracture}< 35$
$$f_{test}=\cfrac{R_{p1.0/T_{test}}}{1.05}$$
$\text{else}$
$$f_{test}=\cfrac{R_{p0.2/T_{test}}}{1.05}$$

### Maximum allowed value of the nominal design stress for assembly cases

$\text{if }\ \text{type }$$\text{of }$$\text{material}= \text{Cast steels}$
$$f_A=\min\left(\cfrac{R_{p0.2/T_{assembly}}}{1.9}, \cfrac{R_{m/20}}{3}\right)$$
$\text{else if }\ \text{type }$$\text{of }$$\text{material}= \text{Austenitic steels}\wedge\text{min. }$$\text{elongation }$$\text{after }$$\text{fracture}\geq 35$$f_A=\max\left[\cfrac{R_{p1.0/T_{assembly}}}{1.5}, \min\left(\cfrac{R_{p1.0/T_{assembly}}}{1.2}, \cfrac{R_{m/T_{assembly}}}{3}\right)\right]$$\text{else if }\ \text{type }$$\text{of }$$\text{material}= \text{Austenitic steels}\wedge 30\le \text{min. }$$\text{elongation }$$\text{after }$$\text{fracture}< 35$
$$f_A=\cfrac{R_{p1.0/T_{assembly}}}{1.5}$$
$\text{else}$
$$f_A=\min\left(\cfrac{R_{p0.2/T_{assembly}}}{1.5}, \cfrac{R_{m/20}}{2.4}\right)$$

### Shape factors for calculation of flat ends of non-circular shape

$\text{if }\ \cfrac{a'}{b'}\le 0.16$
$$C_4=0.75$$
$\text{else if }\ \cfrac{a'}{b'}< 0.363$
$$C_4=0.75-0.44+\sqrt{0.44^2-\left(\cfrac{a'}{b'}-0.16\right)^2}$$
$\text{else}$
$$C_4=-0.6117\cdot \cfrac{a'}{b'}+0.9224$$

### Shape factors for calculation of flat ends of non-circular shape

$$C_3=\sqrt{C_4+\cfrac{6\cdot W\cdot c}{P\cdot n\cdot t_B\cdot a'^2}}$$

### Thickness of the flat end

$$e=\max\left(C_3\cdot a'\cdot\sqrt{\cfrac{P}{f_d}}, C_3\cdot a'\cdot\sqrt{\cfrac{P_{test}}{f_{test}}}\right)$$

### Minimum thickness for the flanged extension

$$e_1=\sqrt{\cfrac{6\cdot W\cdot c}{n\cdot t_B\cdot\min\left(f_d, f_{test}, f_A\right)}}$$