Standard reference
ASME B16.48 Line Blanks
ASME B16.48 addresses operational line blanks within its scope. Distinguish a spectacle blind, a separate spade and a ring spacer from a bolted blind flange.
Identify the line-blank arrangement
A spectacle blind combines an open ring and a solid blank. A separate spade provides the solid element, while a ring spacer provides an open flow path in the corresponding joint arrangement. Specify the actual form rather than using blind flange as a catch-all description.
Fit within the flange joint
Confirm nominal size, class, material, facing and the surrounding flange and gasket arrangement against the specified edition. The blank or spacer must fit the intended joint. Dimensions taken from a bolted blind flange are not a substitute for the line-blank requirements.
Operational and safety requirements
Changing a line blank is an isolation operation governed by the site procedure and an approved work system. An enquiry guide is not a procedure for working on a pressurised line. Provide identification, handling and inspection requirements with the engineering specification.
Selection reference only. Offered scope, technical compliance and availability are confirmed against the complete project enquiry.
Standard scope and ordering designation
Use ASME B16.48 only within its applicable scope. Obtain numerical dimensions and rating tables from the governing standard and the approved project documentation.
| Parameter / designation | Technical information | Selection requirement |
|---|---|---|
| Standard and edition | ASME B16.48 | Record the exact edition and applicable type/series in the purchase description. |
| Scope | ASME B16.48 addresses operational line blanks within its scope. Distinguish a spectacle blind, a separate spade and a ring spacer from a bolted blind flange. | Check size, material and component scope before applying any table. |
| Dimensional designation | Nominal size, series/type, rating designation and dimensional units. | Matching nominal size does not prove matching bolt circle, thickness or facing. |
| Material-dependent rating | Material group, design temperature and any standard-specific rating rules. | Do not read a class number as a direct pressure limit or transfer ratings between materials. |
| Related requirements | Gaskets, fasteners, attachment welds and the project piping/equipment code. | The flange standard does not replace complete assembly design or installation requirements. |
| Legacy or alternate designations | Existing drawing number, original standard and proposed replacement designation. | Verify dimensions and suitability rather than assuming historical names are equivalent. |
Compare related options
Compare ASME B16.48 Line Blanks with the related forms or references below. A related product is not necessarily a permissible substitute.
| Related product / reference | Distinction | Check before selection |
|---|---|---|
| ASME B16.5 Flanges | An ASME B16.5 enquiry identifies the flange type, nominal size, class, material and facing under the specified edition. The standard name alone does not define a complete joint. | ASME B16.5 edition, flange type, NPS and class |
| Raised Face (RF) Flanges | A raised face provides a gasket seating surface inside the bolt circle. Specify the face dimensions, finish and gasket as a coordinated joint requirement. | RF dimensions under the exact flange standard and designation |
| Flange Types Guide | Start with the pipe or equipment connection, then choose a flange form that fits the design and maintenance requirements. A flange name does not select its material or rating. | Butt weld, slip-on, socket weld, thread or stub-end arrangement |
Inspection, documents and delivery
Define acceptance requirements for ASME B16.48 Line Blanks in the purchase order. Required examinations and documents depend on the material, design and project specification.
| Review stage | Information to confirm | Order requirement |
|---|---|---|
| Material identity and traceability | Specification, grade, heat/lot identification and the required material certificate. | Agree documentation and marking before manufacture; visual appearance cannot verify alloy identity. |
| Dimensional verification | Critical dimensions from the selected standard or controlled drawing. | Identify inspection points, tolerances, units and drawing revision. |
| Surface and end condition | Gasket-contact surface, attachment end, edges and any coating exclusions. | State finish and visual acceptance criteria; agree protection of machined surfaces. |
| Supplementary examinations | Any specified PMI, NDE, hardness, impact, corrosion or other tests. | Define the method, sampling and acceptance criteria; tests are not automatically included. |
| Assembly compatibility | Adjoining components, weld or mechanical interface and project service conditions. | Design approval and correct assembly remain separate from a dimensional inspection report. |
| Packing and order release | Quantity, identification, surface protection, documents and delivery destination. | Agree preservation, packaging and release requirements with the order. |
Enquiry checklist
Details for ASME B16.48
Specify the complete joint and design conditions. This checklist is not a dimensional table or an engineering approval.
| Item | Requirement |
|---|---|
| Form | Spectacle blind, spade or ring spacer |
| Reference | B16.48 edition, size, class and material |
| Joint | Facing, gaskets and mating flange arrangement |
| Project | Identification, drawing and inspection requirements |
Continue the specification