{"id":6412,"date":"2026-10-16T02:21:16","date_gmt":"2026-10-16T02:21:16","guid":{"rendered":"https:\/\/www.henghuahose.com\/?p=6412"},"modified":"2026-10-16T02:21:19","modified_gmt":"2026-10-16T02:21:19","slug":"epdm-steam-hose-170c-vs-230c","status":"publish","type":"post","link":"https:\/\/www.henghuahose.com\/fr\/epdm-steam-hose-170c-vs-230c\/","title":{"rendered":"EPDM Steam Hose 170C vs 230C: Which Rating Do You Need?"},"content":{"rendered":"

Which rating you need: match the grade to the steam condition, never to the higher number. A steam hose temperature rating states the highest continuous steam temperature a hose may carry, so the 170 \u00b0C grade and the 230 \u00b0C grade answer two different jobs. The steam hose 170 \u00b0C grade covers saturated steam to about 7 bar g, and the steam hose 230 \u00b0C grade reaches about 26 bar g. This guide reads both grades against the saturation curve, then shows which one your line really needs.<\/p>\n\n\n\n

Match the Grade to the Steam Condition, Not to the Higher Number<\/h2>\n\n\n\n

The 170 \u00b0C grade and the 230 \u00b0C grade share one pressure class, so the real choice is a temperature decision. Each is rated 250 psi (17 bar) working pressure with a 2,500 psi (about 172 bar) burst pressure, a 10:1 safety ratio and a \u221240 \u00b0C cold limit. The difference sits in the continuous ceiling: 170 \u00b0C for one grade, 230 \u00b0C for the other. Choose the grade whose continuous limit stays above the hottest steam the hose will see for most of its working hours.<\/p>\n\n\n\n

The steam hose 170 \u00b0C grade is the general-purpose option for standard steam lines. Its continuous limit is 170 \u00b0C and its intermittent limit is 210 \u00b0C. The steam hose 230 \u00b0C grade is built for the top of the rubber envelope, with a 230 \u00b0C continuous limit and a 250 \u00b0C intermittent limit.<\/p>\n\n\n\n

Read any steam hose rating as two numbers that travel together: a working pressure and the steam temperature at which that pressure applies. A pressure alone is not a steam hose temperature rating, because the tube softens as the steam gets hotter. That is why the pressure versus temperature derating rule<\/a> matters on a steam line.<\/p>\n\n\n\n

What the 170 \u00b0C and 230 \u00b0C Ratings Actually Cover<\/h2>\n\n\n\n

Each grade publishes four numbers that decide a job: a continuous temperature, an intermittent temperature, a working pressure and a burst pressure. Table 1 sets the two grades side by side. The pressure figures are identical for both, so the whole choice turns on temperature.<\/p>\n\n\n\n

Grade<\/th>Continuous steam temperature<\/th>Intermittent steam temperature<\/th>Pression de service<\/th>Burst pressure<\/th>Safety ratio<\/th><\/tr><\/thead>
Steam hose 170 \u00b0C grade<\/th>170 \u00b0C<\/td>210 \u00b0C<\/td>250 psi (17 bar)<\/td>2,500 psi (172 bar)<\/td>10:1<\/td><\/tr>
Steam hose 230 \u00b0C grade<\/th>230 \u00b0C<\/td>250 \u00b0C<\/td>250 psi (17 bar)<\/td>2,500 psi (172 bar)<\/td>10:1<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Identical pressure does not mean interchangeable hose. The continuous temperature separates the grades, and the steam hose material behind each one is compounded for a different heat load. The 170 \u00b0C tube is cured for steady steam below its ceiling. The 230 \u00b0C tube uses a peroxide-cured, wrapped cover for the hottest duty. That difference is why the 170 \u00b0C grade and the 230 \u00b0C grade cannot be swapped on price alone.<\/p>\n\n\n\n

Both grades share a seamless EPDM tube and a pin-pricked cover in red or blue, over one or two steel wire braid layers. The bore range for both runs from 3\/8 inch to 4 inch (10 mm to 102 mm), and every length is proof-tested at 1.5 times working pressure. The 230 \u00b0C hose construction explains the peroxide cure, and the EPDM steam hose 170 \u00b0C range<\/a> lists the standard bores and lengths.<\/p>\n\n\n\n

A steam hose temperature rating is a continuous figure first. The intermittent number is a short-term allowance, not a normal working condition. A hose rated for 210 \u00b0C intermittent and 170 \u00b0C continuous should still be specified at or below 170 \u00b0C for daily service. Treat the higher number as a cushion for warm-up and for short upsets, never as the design point. That habit alone prevents most premature replacements.<\/p>\n\n\n\n

\"Table<\/figure>\n\n\n\n

Figure 2. The two EPDM grades compared on continuous temperature, intermittent limit and shared pressure rating.<\/p>\n\n\n\n

Steam Hose Temperature Rating Against Saturated Steam Pressure<\/h2>\n\n\n\n

For saturated steam the temperature is fixed by the pressure, so one column drives the choice. Table 2 pairs gauge pressure with temperature and names the grade that carries it continuously. Values follow the IAPWS-IF97 steam tables and sit inside the ISO 6134 envelope.<\/p>\n\n\n\n

Gauge pressure (bar g)<\/th>Saturated steam temperature<\/th>Grade needed<\/th><\/tr><\/thead>
1<\/th>120 \u00b0C<\/td>170 \u00b0C grade<\/td><\/tr>
3<\/th>144 \u00b0C<\/td>170 \u00b0C grade<\/td><\/tr>
5<\/th>159 \u00b0C<\/td>170 \u00b0C grade<\/td><\/tr>
6<\/th>165 \u00b0C<\/td>170 \u00b0C grade<\/td><\/tr>
7<\/th>170 \u00b0C<\/td>170 \u00b0C grade, at the limit<\/td><\/tr>
8<\/th>175 \u00b0C<\/td>230 \u00b0C grade<\/td><\/tr>
10<\/th>184 \u00b0C<\/td>230 \u00b0C grade<\/td><\/tr>
12<\/th>192 \u00b0C<\/td>230 \u00b0C grade<\/td><\/tr>
14<\/th>198 \u00b0C<\/td>230 \u00b0C grade<\/td><\/tr>
16<\/th>204 \u00b0C<\/td>230 \u00b0C grade<\/td><\/tr>
17<\/th>207 \u00b0C<\/td>230 \u00b0C grade<\/td><\/tr>
18<\/th>210 \u00b0C<\/td>230 \u00b0C grade<\/td><\/tr>
20<\/th>215 \u00b0C<\/td>230 \u00b0C grade<\/td><\/tr>
25<\/th>226 \u00b0C<\/td>230 \u00b0C grade<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

The boundary is easy to remember. The 170 \u00b0C grade covers gauge pressure to about 7 bar g, where the steam sits near 170 \u00b0C. Above that line the 230 \u00b0C grade takes over and carries the same duty to about 26 bar g. A steam hose rating printed on a label holds only while the steam stays at or below the ceiling for that grade. The steam hose temperature rating that matters is the continuous one, not the peak.<\/p>\n\n\n\n

\"Chart<\/figure>\n\n\n\n

Figure 3. Grade decision chart: the pressure and temperature range where each EPDM grade is the correct choice.<\/p>\n\n\n\n

Why 17 Bar Saturated Steam Rules Out the 170 \u00b0C Grade<\/h2>\n\n\n\n

Seventeen bar g of steam sits at about 207 \u00b0C. That is far above the 170 \u00b0C continuous limit, so the 170 \u00b0C grade cannot carry it, even though both grades share a 250 psi (17 bar) working pressure. The duty keeps the pressure but breaks the temperature, and a steam hose failure on heat is the usual result. Heat, not strength, is what ends the hose.<\/p>\n\n\n\n

A steam hose working pressure is a limit at a stated temperature, not at any temperature. The 250 psi (17 bar) figure applies at the rated steam temperature for the grade. Push the steam hotter than the ceiling and the tube ages fast, the bond weakens, and the assembly may burst well below its nominal pressure. That is the whole steam hose safety margin, spent by heat rather than by pressure. The steam hose material, not the pressure class, sets the ceiling.<\/p>\n\n\n\n

The steam hose temperature rating of a grade is the number a buyer should compare, not the burst pressure alone. Two hoses can share a 2,500 psi (about 172 bar) burst figure and still behave very differently above 170 \u00b0C. The tube compound and the cure set that limit, and the rating is simply the visible result of both. When a supplier quotes only the burst figure, ask for the continuous temperature as well.<\/p>\n\n\n\n

ISO 6134:2024 draws its own ceiling for the standard. Type 1 hose is rated 6 bar at 164 \u00b0C with textile reinforcement, and Type 2 hose is rated 18 bar at 210 \u00b0C with steel wire reinforcement. A 17 bar duty sits inside Type 2 territory, which points to steel wire braid and the hotter grade. The saturated and superheated steam comparison explains why the same pressure can still need the higher grade.<\/p>\n\n\n\n

Four Questions That Decide Between 170 \u00b0C and 230 \u00b0C<\/h2>\n\n\n\n

Four questions settle the choice on most plants. Ask them in order and the answer usually falls out on its own.<\/p>\n\n\n\n