Line Blanks — Companion Article

Open the tool: https://pipingdesigners.com/tools-training/line-blanks/

What this tool does

Line Blanks is a lookup for spectacle blinds (figure-8 blanks), spacers and blind disks. Pick a class, a size and a type, and it shows the dimensions and a sketch.

When to use it

Use it when laying out a positive isolation point, to check the space a blind needs, or to size the swing room for a spectacle blind.

Inputs

• Class: 150, 300, 600 or 900.
• Nominal size, NPS 1 to NPS 24 where the chart lists it.
• Type: spectacle blank, spacer or blind disk.
• Units: inches or millimetres.

How it works

The page reads a bundled manufacturer chart. Millimetres are the inch figures × 25.4. A spacer has no centreline, and a blind disk has no inside diameter, so those fields are left off.

Understanding the result

Each dimension shows as a card. On a phone you can open a full table that scrolls sideways.

Engineering considerations

• Check the blind’s thickness for your design pressure and temperature. A chart thickness is not a design check.
• Make sure there is room to spread the flanges and swing the blind.

Example

Class 150 NPS 8 spectacle blank: thickness 0.5 in, centreline 11.75 in.

Standards/references (licensed vs interim)

Licence status is interim. The numbers come from the Texas Flange line blank chart, with a class 150 cross-check against a second manufacturer chart, not from licensed ASME B16.48 text. The page builds its source note from the dataset and names the standard to verify against. Always check the current edition of ASME B16.48, or the manufacturer’s certified drawing, before you use a figure on a deliverable.

Limitations/disclaimer

• Classes 150 to 900 only. No NPS 1/2, 3/4, or above 24 yet.
• Where the two charts differ, the page keeps the primary figure and says so.
• The result is preliminary and needs engineering review.

Use the tool

Calculate now: Line Blanks

Related tools

• The flange datasheet tool for flange dimensions. Read the flange datasheet companion article.
• The gaskets tool. Read the gaskets companion article.