Probably you sit in a meeting and you need to quickly estimate the temperature of saturated steam using a calculator instead of finding it in a steam table such as the IAPWS-IF97 formula. You could actually do that pretty accurately by doubling the square root of that steam pressure in barA as shown below:

Tsat = [(P^0.5)^0.5]x100
where;
    P   = Saturated Steam Pressure (barA)
    Tsat= Saturated Steam Temperature (degC)
    Note: the pressure is in abs not gauge.

Now let’s check how acceptable this method is vs IF97.

Sat. Steam Pres.
(barA)		 Temp w/ IF97
(degC)		 Temp w/ double sqroot
(degC)		 Error %
1 99.606 100.000 0.40
2 120.212 118.921 1.07
4 143.613 141.421 1.53
6 158.832 156.508 1.46
8 170.414 168.179 1.31
10 179.886 177.828 1.14
20 212.385 211.474 0.43
40 250.358 251.487 0.45
60 275.586 278.316 0.99
80 295.009 299.070 1.38
100 310.999 316.228 1.68

The error is less than 2%! Pretty reliable.

Bonus reference: Typical saturated steam condition from the plant utility.

Steam Type Pressure (barG) Pressure (barA)
Low Pressure (sat) Steam 5.5 4.5
Desuperheated Medium Pressure Steam 17 16
Desuperheated High Pressure Steam 47 46