{"id":44100,"date":"2026-07-25T18:57:21","date_gmt":"2026-07-25T18:57:21","guid":{"rendered":"https:\/\/valve-atlas.com\/2026\/07\/25\/nace-mr0175-sour-service-guide\/"},"modified":"2026-07-25T18:57:21","modified_gmt":"2026-07-25T18:57:21","slug":"nace-mr0175-sour-service-guide","status":"publish","type":"post","link":"https:\/\/valve-atlas.com\/fr_ca\/2026\/07\/25\/nace-mr0175-sour-service-guide\/","title":{"rendered":"Explication de la norme NACE MR0175\u00a0: Quand la conformit\u00e9 aux normes relatives aux services acides est-elle obligatoire\u00a0?"},"content":{"rendered":"<p>NACE MR0175 (now ISO 15156) appears on valve RFQs constantly &mdash; sometimes where it is essential, often where it adds cost for nothing. Here is what it actually requires and when you genuinely need it.<\/p>\n<h2>What Problem NACE MR0175 Solves<\/h2>\n<p>In <strong>sour service<\/strong> &mdash; hydrocarbon systems containing wet hydrogen sulfide (H2S) above defined partial-pressure thresholds &mdash; ordinary high-strength steels can fail suddenly by <strong>sulfide stress cracking (SSC)<\/strong>. MR0175 controls the materials: chemistry, hardness limits (typically max 22 HRC for carbon steels), heat treatment and welding, so components resist SSC.<\/p>\n<h2>When It Applies<\/h2>\n<ul>\n<li>Upstream oil &amp; gas production, gathering and processing with H2S partial pressure above 0.05 psia (0.3 kPa) in the wet phase &mdash; the classic trigger.<\/li>\n<li>Sour gas transport and treating (amine units and similar).<\/li>\n<li>Refinery units only where the licensor or owner spec extends it.<\/li>\n<\/ul>\n<h2>When It Does NOT Apply<\/h2>\n<ul>\n<li>Fire-water systems &mdash; never. Specify UL\/FM or API 607 fire-safe instead; see our <a href=\"\/2026\/07\/25\/api-607-fire-safe-vs-ul-fm\/\">API 607 vs UL\/FM guide<\/a>.<\/li>\n<li>Steam, air, water, glycol and sweet gas systems.<\/li>\n<li>Stainless food\/pharma lines &mdash; hygiene standards govern, not NACE.<\/li>\n<\/ul>\n<h2>What It Changes on a Valve<\/h2>\n<p>Body: LCB\/LCC or WCB with hardness control; trim: 316\/duplex within H2S limits, or Inconel 625 overlay; bolting: B7M\/2HM (softer than standard B7); plus PMI and hardness test reports in the document package. Expect a price premium and longer lead time &mdash; which is why specifying it needlessly hurts your bid.<\/p>\n<h2>Foire aux questions<\/h2>\n<h3>Is NACE compliance a certificate?<\/h3>\n<p>No single &ldquo;NACE certificate&rdquo; exists &mdash; compliance is declared by the manufacturer and evidenced through material certs, hardness reports and heat-treatment records. Ask for a compliance statement referencing ISO 15156 part and materials annex.<\/p>\n<h3>MR0175 vs MR0103 &mdash; which one?<\/h3>\n<p>MR0175\/ISO 15156 covers upstream production environments; NACE MR0103 (ISO 17945) covers refinery process units. Downstream specs usually call MR0103.<\/p>\n<h3>Can duplex stainless be used in sour service?<\/h3>\n<p>Yes within the H2S\/chloride\/temperature envelope defined in ISO 15156-3 &mdash; duplex has limits, not a blanket approval. See our <a href=\"\/stainless-steel-valves\/\">stainless &amp; duplex valve range<\/a>.<\/p>\n<p><em>Quoting a sour-service package? <a href=\"\/contact\/\">ValveAtlas supplies NACE-compliant valves with full documentation<\/a>.<\/em><\/p>","protected":false},"excerpt":{"rendered":"<p>NACE MR0175 (now ISO 15156) appears on valve RFQs constantly &mdash; sometimes where it is essential, often where it adds cost for nothing. Here is what it actually requires and when you genuinely need it. What Problem NACE MR0175 Solves In sour service &mdash; hydrocarbon systems containing wet hydrogen sulfide (H2S) above defined partial-pressure thresholds&hellip;<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"iawp_total_views":0,"footnotes":""},"categories":[21],"tags":[],"class_list":["post-44100","post","type-post","status-publish","format-standard","hentry","category-industry","category-21","description-off"],"acf":[],"_links":{"self":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts\/44100","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/comments?post=44100"}],"version-history":[{"count":0,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/posts\/44100\/revisions"}],"wp:attachment":[{"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/media?parent=44100"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/categories?post=44100"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/valve-atlas.com\/fr_ca\/wp-json\/wp\/v2\/tags?post=44100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}