This International Standard specifies a method for the determination of the vapour pressure of liquid petroleum<\/p>\n
products consisting of essentially or wholly of hydrocarbon components, or containing oxygenated hydrocarbons of<\/p>\n
specific types and at specified maximum concentrations. The method does not apply outside these concentration<\/p>\n
levels, nor to any blends containing methanol or other oxygenated hydrocarbons not covered in note 1.<\/p>\n
NOTE 1 The maximum concentration of ethers containing 5 or more carbon atoms is 15 % (V<\/i>\/V<\/i>), and for ethanol is 10 %<\/p>\n
(V<\/i>\/V<\/i>). For higher alcohols, the maximum concentration is 7 % (V<\/i>\/V<\/i>).<\/p>\n
NOTE 2 For the purposes of this International Standard, the term "%(V\/V)" is used to represent the volume fraction of a<\/p>\n
material.<\/p>\n
For petroleum products containing methanol, or other oxygenated hydrocarbons outside the scope of note 1, a dry<\/p>\n
vapour-pressure test method should be used. For liquefied petroleum gases, ISO 4256 should be used. The test<\/p>\n
method may be applied to volatile crude petroleum with a vapour pressure exceeding 10 kPa, although the<\/p>\n
precision has not been evaluated.<\/p>\n
Four procedures are described in this International Standard. Procedures A and B are alternative apparatus<\/p>\n
configurations for products with a Reid vapour pressure up to 180 kPa, Procedure C is applied to liquid products<\/p>\n
with a Reid vapour pressure above 180 kPa, and Procedure D applies to aviation gasolines with a Reid vapour<\/p>\n
pressure of approximately 50 kPa.<\/p>\n
Vapour pressure is an important physical property of volatile liquids, and has critical performance implications for<\/p>\n
automotive and aviation gasolines. Vapour pressure is also one of the properties affecting atmospheric evaporation,<\/p>\n
and is therefore increasingly used in regulations relating to emissions and air quality control. Vapour pressure is<\/p>\n
also a critical property limiting the performance and safety of operation of equipment during transfer operations.<\/p>\n
NOTE Because the external atmospheric pressure is counteracted by the atmospheric pressure initially in the vapour<\/p>\n
chamber, the Reid vapour pressure is approximately the "absolute" vapour pressure at 37,8 \u00b0C. The Reid vapour pressure<\/p>\n
differs from the true vapour pressure of the sample owing to slight vaporization of the sample and the pressure of water vapour<\/p>\n
and air in the confined space.<\/p>\n","protected":false},"excerpt":{"rendered":"
Petroleum products and crude petroleum \u2014 Determination of vapour pressure \u2014 Reid method<\/b><\/p>\n\n\n
\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n ISO<\/b><\/a><\/td>\n 1999-10<\/td>\n 22<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":612411,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[1067,2634],"product_tag":[],"class_list":{"0":"post-612399","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-75-080","7":"product_cat-iso","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/612399","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/612411"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=612399"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=612399"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=612399"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}