ASME B16.48
Line blanks — spectacle blinds, spacers and paddle blanks
Covers line blanks — spectacle blinds, paddle blanks and spacers — used to isolate piping, sized to fit between B16.5 and B16.47 flanges.
- Dimensional standards
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is ASME B16.48?
ASME B16.48 is the standard for line blanks — figure-8 (spectacle) blinds, paddle blanks and paddle spacers installed between flanges to isolate a line. It sets thicknesses and dimensions by pressure class so the blank can safely hold full line pressure. Material is named separately.
ASME B16.48 at a glance
| Products | Spectacle (figure-8) blinds, paddle blanks, paddle spacers |
|---|---|
| Classes | 150 to 2500 |
| Purpose | Positive isolation of piping for maintenance or testing |
How to write ASME B16.48 on a purchase order
Name the product, size, material specification and grade, the dimensional standard and the certificate. An example line:
Illustrative only — sizes, tests, inspection level and any project values come from your purchase specification.
ASME B16.48 edition and verification status
Which edition we have confirmed, and what is still being checked before any numerical requirement is published here.
| Current edition | Not yet confirmed against the publisher listing |
|---|---|
| Full-text verification | In progress — numerical requirements are not published on this page |
| Edition on your order | The edition named in your purchase order or design code governs — confirm it with your enquiry |
What to know before ordering to ASME B16.48
The points that decide whether material to ASME B16.48 is accepted at inspection.
- Thickness depends on pressure class and size.
- Spectacle blinds combine a blank and a spacer in one piece.
- Material is usually cut from plate or forged to the flange specification.
How ASME B16.48 fits into an order
A purchase order line is only complete when it names the material standard, the dimensional standard and the inspection document. Miss one and the mill, the inspector and the buyer can each read the order differently.
Standards used with ASME B16.48
Same family
ASME B16.48 — questions buyers ask
What is ASME B16.48?
ASME B16.48 is the standard for line blanks — figure-8 (spectacle) blinds, paddle blanks and paddle spacers installed between flanges to isolate a line. It sets thicknesses and dimensions by pressure class so the blank can safely hold full line pressure. Material is named separately.
What is a spectacle blind?
A figure-8 shaped plate with one solid and one open end; it is rotated to isolate or open the line.
Does ASME B16.48 specify the material?
No. ASME B16.48 sets dimensions; the material comes from a separate specification such as ASTM A182, A105 or B564 for flanges, or A403 and B366 for fittings. A complete order names both.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026