ANSI MSS SP-25-2018 pdf free download – STANDARD MARKING SYSTEM FOR VALVES, FITTINGS, FLANGES, AND UNIONS.
1.1 This standard marking system applies to the marking of new valves,fittings,flanges, and unionsused in piping connections that include (but are not limited to) flanged, soldered, brazed, threaded, orwelded joints.
1.2 The markings specified within this Standard Practice serve to identify the manufacturer, the ratingdesignation, materials of construction, and special service limitations imposed by the manufacturer.Theyare used for product identification and to assist in proper application.
1.3 Marking for remanufactured and refurbished valves, fittings, flanges, and unions is outside the scopeof this Standard Practice.
2. GENERALMARKING REOUIREMNTS
2.1 Each product, of a size and shape permitting legible marking, shall be marked in accordance with theprovisions of this Standard Practice.
2.2 Markings shall be applied to the body of valves,flanges, fittings, and union components, or on anidentification plate. For quarter-turn valves, markings shall be applied to the body, identification plate, orhandle. Markings on covered quarter-turn valve handles may not be integral with the base handle material.2.3Markings shall consist of numerals，letters, or symbols that are cast,forged, stamped, electro-etched,vibro-etched, laser-etched, or otherwise made integral with the product, or as markings on an identificationplate attached to the product, or both. Where stamping is used on pressure containing walls, low stress stampswhich produce a round bottom impression shall be used; such low stress stamps are not required on flangededges or on raised pads provided for marking purposes.
2.4 Markings indicating conformance with recognized documents, such as the ASME Boiler and PressureVessel Codes (BPVC)，or applicable APl,FM, and UL conformance，testing， andor certificationrequirements, may be applied only by authorized, licensed, or approved manufacturers.
Such markings shall be applied only to products fully conforming to the applicable qualification, conformance,andor certification requirements and may be shown on the body or an attached plate, at the option of themanufacturer.
2.5 Manufacturers should apply markings indicating conformance with codes and standards such as API,ASME,ASTM,AWWA, and MSS,on products that fully conform to the applicable codes or standards.Partial compliance markings may apply in specific cases, as allowed for by the code or standard.Certaincodes and standards specify mandatory product conformance markings and methods. Such markings shallbe shown on the body, on an attached plate, or as otherwise specified.
2.6 International and Federal commerce laws，Codes，or contracts may require marking of finishedproducts with country of origin. When required, the markings shall be conspicuous and positioned toprevent concealment during inspection, installation, or use.
2.7 Flow or pressure indication shall be marked on unidirectional valves. Commonly used markingsinclude arrows or the words “inlet” or ““outlet” or “high pressure side”marked at an appropriate end.
2.8 Nothing in this Standard Practice shall be construed as prohibiting the use of additional markings such ascatalog reference numbers, patterm numbers，patent numbers,dates， customer specification numbers， etc.
Product markings that indicate special designs, particular requirements, or special limitations, should also carryadditional special marking to distinguish them from regularly available and standard products.All additionalmarkings shall be applied in such a manner as to avoid confusion with standardized and customary symbols ormarkings.Consult MSS SP-96 for additional definitions of terms and acronyms used in the Standard Practice.3.MANUFACTURER’S NAME OR TRADEMARK
All valves,fittings,flanges, and unions shall be marked with the manufacturer’s name,trademark, logo, orsymbol. See Section 11 for permissible omissions.
4. RATING DESIGNATION
4.1 The expression“Rating Designation”includes the intent of the expressions “Pressure Designation”,“Class Designation “, “Pressure Class” , and similar terms used to define the pressure and temperature limitationsof the product. The rating designation shall be shown by one of the systems in the sections that follow:
4.1.1 The rating designation for products that fully conform to recognized standards may bedesignated by the Class numbers alone (e.g., a steam pressure rating or a pressure class designation).Pressure Rating Values may be abbreviated by using “M” to designate units of one thousand (e.g.,“3M used in place of “3000″).
4.1.2The rating designation for products that may conform to recognized standards,however, are notsuitable for the full range of pressures or temperatures of these standards (where allowed), shall be markedas prescribed in Sections 4.1.3 and 4.1.4, as appropriate, and shall also show the numbers and lettersrepresenting the service limitation at the limiting condition.
4.1.3 The rating designation for products that do not conform to recognized product standards may beshown by numbers and letters representing the pressure ratings at the corresponding temperatures in thefollowing format:
“2000 AT 10OF 725 AT 925F””
The rating designation may also be shown as the maximum pressure followed by “CWP” and theallowed pressure at the maximum temperature, seen in the following format:
“2000 cwP 725 AT 925F”
Products intended for ambient room temperature may show the allowable pressure followed by letterscwP or cquivalent, secn in the following format:
“2000 cwP”
4.1.4 Products with dual or multiple rating designations may be marked with maximum pressure atcWP and the allowable pressure at the maximum temperature, seen in the following format:
“2000 cwP 725 AT 925F”.ANSI MSS SP-25 pdf download.