# What does 150 lbs flange mean?

## What does 150 lbs flange mean?

As temperature increases, the pressure rating of the flange decreases. For example, a Class 150 flange is rated to approximately 270 PSIG at ambient conditions, 180 PSIG at approximately 400°F, 150 PSIG at approximately 600°F, and 75 PSIG at approximately 800°F. Each material have different pressure ratings.

## What is a class 125 flange?

In terms of drilling and flange O.D. 125 class is the same as 150 class and 250 class if the same as 300 class. 1 Class 125 flange is rated for 125 psi at 353ºF (178ºC), which is the boiling temperature for water at that pressure. As temperature increases, the pressure rating of the flange decreases.

What are flange dimensions?

Diameters and bolt circles for standard ASME B16. 5 flanges – 1/4 to 24 inches – Class 150 to 2500

Nominal Pipe Size NPS (inches) Class 400
Diameter of Flange (inches) Diameter of Bolt Holes (inches)
1 4-7/8 0.75
1-1/4 5-1/4 0.75
1-1/2 6-1/8 0.88

What is the difference between a 125 flange and a 150 flange?

1 Class 125 flanges are made from cast iron, ANSI/ASME B16. 5 Class 150 can be made from steel or stainless and ANSI/ASME B16. 42 Class 150 is made from ductile iron. However, the bolting pattern is the same for both Class 125 and 150 so, regardless of material, they will bolt together.

### How is flange rating calculated?

When trying to determine the flange rating of a pump, the best method is to look for a stamp printed onto the flange. If one is not visible, or it is worn, then start by counting the number of bolt holes. This will point you to a narrower range of flange sizes in the chart below.

### What is flange class rating?

The term “flange rating” (or class) refers to the maximum pressure (in psi or bars) that a flange withstands at increasing temperatures. Flanges with a higher rating (class) are stronger than flanges with lower ratings, as they bear more pressure at increasing temperatures.

Is flange a standard?

A flange standard lays down the dimensions, surface finish, facing type, marking, material and technical specifications for flanges. National flange standards in Europe have largely been superseded by the European EN 1092 series.

What is flange rating?

#### What is the difference between a slip on flange and a lap joint flange?

lap joint flanges are very similar to a slip-on flange, with the main difference being that it has a curved radius at the bore and face to house a lap joint stub-end. Lap joint flanges and stub-end assemblies are typically used in situations where frequent dismantling is required for for inspection.