{"id":2589,"date":"2026-07-01T06:03:33","date_gmt":"2026-07-01T06:03:33","guid":{"rendered":"https:\/\/hydrauliccylindersprice.com\/product\/rotary-drilling-pressurized-cylinder\/"},"modified":"2026-07-01T06:03:37","modified_gmt":"2026-07-01T06:03:37","slug":"rotary-drilling-pressurized-cylinder","status":"publish","type":"product","link":"https:\/\/hydrauliccylindersprice.com\/th\/product\/rotary-drilling-pressurized-cylinder\/","title":{"rendered":"Rotary Drilling Pressurized Cylinder"},"content":{"rendered":"

<\/p>\n

<\/p>\n

\n \"Rotary<\/p>\n
\n Rotary Drilling Rig \u00b7 3rd of 3<\/span><\/p>\n

Rotary Drilling Pressurized Cylinder<\/h2>\n

8,500 mm of stroke \u2014 the longest single-stage cylinder in the entire mobile machinery range. This cylinder drives the power head up and down the full length of the drilling mast, pushing the drill tool into the earth with 100\u2013300 KN of crowd force and then lifting it back out with 10\u201330 tonnes of drill string hanging below.<\/p>\n

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8,500mm<\/span>Longest Stroke<\/span><\/div>\n
125\u2013210mm<\/span>Bore<\/span><\/div>\n
35 MPa<\/span>Pressure<\/span><\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/section>\n

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Push Down to Drill, Pull Up to Extract \u2014 The Cylinder That Never Rests<\/span><\/h2>\n
\n \"Rotary<\/p>\n

Every borehole is a cycle of penetration and extraction. The rotary table spins the drill tool, and the pressurized cylinder pushes the power head downward along the mast \u2014 applying “crowd force” that drives the tool into the soil. When the drilling bucket is full (1\u20133 cubic metres of earth), the cylinder reverses: it lifts the power head upward, pulling the kelly bar, drill string, and soil-laden bucket out of the borehole. The operator swings the bucket over the spoil pile, opens it, dumps the soil, swings back, and the cycle repeats.<\/p>\n<\/div>\n

On a typical foundation piling job, this cycle takes 3\u20138 minutes and repeats 50\u2013150 times per pile. A rig drilling 3\u20135 piles per day performs 150\u2013750 crowd-and-extract cycles daily. The pressurized cylinder is the hardest-working cylinder on the drilling rig \u2014 cycling continuously throughout the entire working day with full force in both directions.<\/p>\n

Korea Ever-Power manufactures the pressurized cylinder as the final component of the three-cylinder rotary drilling rig hydraulic cylinder<\/a> system \u2014 alongside the luffing cylinder (#24) and the mast cylinder (#25).<\/p>\n<\/section>\n

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Technical Specifications<\/span><\/h2>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nSpecification<\/th>\n<\/tr>\n<\/thead>\n
Product<\/td>\nRotary Drilling Pressurized Cylinder<\/td>\n<\/tr>\n
Function<\/td>\nControl the lifting and lowering of the power head<\/td>\n<\/tr>\n
Bore Diameter<\/td>\n125 mm \u2013 210 mm<\/td>\n<\/tr>\n
Rod Diameter<\/td>\n90 mm \u2013 150 mm<\/td>\n<\/tr>\n
Stroke<\/td>\n\u2264 8,500 mm (longest in range)<\/td>\n<\/tr>\n
Working Pressure<\/td>\nUp to 35 MPa<\/td>\n<\/tr>\n
Application<\/td>\nRotary Drilling Rig (foundation piling)<\/td>\n<\/tr>\n
Certification<\/td>\nISO 9001 \u00b7 100% hydrostatic tested<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/section>\n

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8,500 mm Stroke \u2014 Why the Power Head Must Travel the Full Mast Length<\/h2>\n

The power head sits on a carriage that rides up and down the mast on guide rails \u2014 like an elevator on its shaft. The pressurized cylinder’s stroke determines how far the power head can travel along the mast, which directly determines the maximum single-pass drilling depth:<\/p>\n

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\n Crowd stroke \u2014 penetration per pass<\/strong><\/p>\n

Each downward stroke of the pressurized cylinder advances the drill tool one “pass” into the earth \u2014 typically 1\u20134 metres per pass depending on soil conditions. The kelly bar (a telescopic square or hexagonal shaft) extends as the power head descends, reaching deeper with each successive section. The 8,500 mm cylinder stroke matches the kelly bar section length, ensuring the full drilling depth of each kelly section is utilised in a single pass.<\/p>\n<\/p><\/div>\n

\n Extraction stroke \u2014 pulling the drill string<\/strong><\/p>\n

After each pass, the cylinder retracts to lift the power head, kelly bar, and soil-laden bucket back to the mast top. The extraction force must overcome the combined weight of the drill string plus the friction of the bucket walls against the borehole walls \u2014 potentially 15\u201330 tonnes pulling upward. The annular piston area (bore\u00b2 \u2212 rod\u00b2) \u00d7 35 MPa must produce enough retraction force for the heaviest soil load. Contact Korea Ever-Power engineering<\/a> for crowd\/extraction force calculations.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/section>\n

<\/p>\n

\n \"Pressurized
\n<\/section>\n

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Drilling Mud, Bentonite, and Concrete \u2014 The Harshest Contamination on Any Cylinder<\/span><\/h2>\n
\n \"Drilling<\/p>\n

The pressurized cylinder’s exposed rod section \u2014 up to 8,500 mm of chrome surface cycling in and out of the barrel \u2014 operates in the most contaminated environment of any cylinder in the mobile machinery range. Drilling rigs use bentonite slurry (a clay-water mixture) to stabilise boreholes, and this slurry coats every surface of the rig during operation. Bentonite is abrasive when it dries and highly adhesive when wet \u2014 it clings to the rod surface and can be dragged past the wiper seal into the barrel.<\/p>\n<\/div>\n

On piled foundation sites, concrete slurry from the pile-pouring process adds a further contamination threat. Cement particles that enter the seal zone harden within hours \u2014 creating an abrasive paste that destroys the seal lip and scores the rod chrome.<\/p>\n

Korea Ever-Power specifies a triple wiper system for the pressurized cylinder \u2014 primary wiper + secondary wiper + buffer seal \u2014 with a mud-guard boot covering the rod’s exit point. Chrome plating thickness is 80 \u00b5m minimum (the heavy end of the range) to provide maximum resistance to abrasive contamination.<\/p>\n<\/section>\n

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Manufacturing Process<\/span><\/h2>\n

The 8,500 mm stroke requires an overall cylinder length exceeding 9,000 mm when retracted \u2014 among the longest single-stage cylinders Korea Ever-Power produces. Deep-hole boring (for barrels where seamless tube is not available), precision honing to Ra 0.2\u20130.4 \u00b5m, and rod straightness \u22640.1 mm\/metre across the full 8.5-metre rod are performed on dedicated long-stroke machining centres. The rod’s chrome plating is applied in a vertical plating tank specifically designed for rods exceeding 6 metres.<\/p>\n

Seals are polyurethane piston seal + triple wiper + buffer seal stack, rated for -30 \u00b0C to +80 \u00b0C and 35 MPa. The cylinder is hydrostatic tested at 1.5\u00d7 rated pressure (52.5 MPa) and full-stroke cycled 10 times to verify smooth operation across the entire 8,500 mm travel \u2014 checking for stick-slip, seal drag, and rod deflection at full extension.<\/p>\n<\/section>\n

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OEM & ODM<\/span><\/h2>\n
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What You Provide<\/strong><\/div>\n
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Rig model, mast height, kelly bar section length, maximum crowd force, maximum extraction weight (kelly + bucket + soil), power head travel speed (crowd and extraction), bore\/rod\/stroke or force requirement, system pressure, contamination protection requirement, and the mast carriage\/guide rail assembly drawing.<\/p>\n<\/div><\/div>\n

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What the Factory Delivers<\/strong><\/div>\n
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Engineering drawing with bore, rod, 8,500 mm stroke, triple wiper specification, 80 \u00b5m chrome plating, seal specification, mud-guard boot provisions, and mounting dimensions. Hydrostatic + full-stroke functional test. Seal kits. Browse the mobile machinery hydraulic cylinder family<\/a> and the Korea Ever-Power catalogue<\/a>.<\/p>\n<\/div><\/div>\n<\/p><\/div>\n

\"Korea
\n<\/section>\n

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FAQ<\/span><\/h2>\n
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Is the pressurized cylinder single-stage or multi-stage?<\/h3>\n

Single-stage. Unlike the crane telescopic cylinder (#18) which uses multiple nested stages, the pressurized cylinder achieves its 8,500 mm stroke from a single barrel and rod \u2014 because it operates vertically inside the mast where there is no length constraint. The single-stage design provides maximum hydraulic stiffness for crowd-force control, which is critical for drilling penetration rate management.<\/p>\n<\/p><\/div>\n

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How does bentonite contamination affect cylinder life?<\/h3>\n

Bentonite is the primary cause of seal failure on drilling rig cylinders. Dried bentonite particles act as an abrasive paste \u2014 scoring the rod chrome and cutting the wiper seal lip. Korea Ever-Power’s triple wiper + mud-guard boot system extends seal life by 2\u20133\u00d7 compared to a standard double-wiper arrangement. Seal replacement intervals on drilling rig cylinders are typically 2,000\u20134,000 operating hours \u2014 shorter than crane cylinders due to the contamination intensity.<\/p>\n<\/p><\/div>\n

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Can Korea Ever-Power supply all three rotary drilling cylinders together?<\/h3>\n

Yes \u2014 luffing (#24), mast (#25), and pressurized (#26) cylinders are supplied as a coordinated set matched to the same rig’s hydraulic system. Single-source supply from Korea Ever-Power ensures pressure compatibility, seal standardisation, and coordinated delivery scheduling. Browse telescopic cylinders<\/a> and industrial engineering cylinders<\/a> for other long-stroke applications.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<\/section>\n

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Related Categories<\/span><\/h2>\n
<\/p>\n
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\"Telescopic\"<\/div>\n
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Telescopic Hydraulic Cylinders \u2192<\/div>\n
Dump truck, trailer, hoist.<\/div>\n<\/div>\n<\/div>\n

<\/a><\/p>\n

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\"Forklift\"<\/div>\n
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Forklift Hydraulic Cylinders \u2192<\/div>\n
Lift, tilt, steer \u2014 OEM.<\/div>\n<\/div>\n<\/div>\n

<\/a><\/p>\n

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\"AWV\"<\/div>\n
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Aerial Work Vehicle Cylinders \u2192<\/div>\n
Scissor, boom, platforms.<\/div>\n<\/div>\n<\/div>\n

<\/a><\/div>\n<\/section>\n

<\/main><\/p>","protected":false},"excerpt":{"rendered":"

Rotary drilling pressurized cylinder \u2014 the hydraulic actuator that moves the power head (rotary table) up and down the mast, applying the downward crowd force that drives the drilling tool into the earth. Stroke up to 8,500 mm \u2014 the longest single-stage stroke in the mobile machinery range \u2014 because the power head must travel the full length of a 20\u201330 metre drilling mast. Working pressure up to 35 MPa. Bore 125\u2013210 mm. The third and final rotary drilling rig cylinder from Korea Ever-Power. ISO 9001. OEM & ODM.<\/div>","protected":false},"featured_media":2590,"comment_status":"closed","ping_status":"open","template":"","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":""},"product_brand":[],"product_cat":[854],"product_tag":[],"class_list":["post-2589","product","type-product","status-publish","has-post-thumbnail","product_cat-mobile-machinery-hydraulic-cylinders","pa_editor-cxm","first","instock","product-type-simple"],"_links":{"self":[{"href":"https:\/\/hydrauliccylindersprice.com\/th\/wp-json\/wp\/v2\/product\/2589","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hydrauliccylindersprice.com\/th\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/hydrauliccylindersprice.com\/th\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/th\/wp-json\/wp\/v2\/comments?post=2589"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/th\/wp-json\/wp\/v2\/media\/2590"}],"wp:attachment":[{"href":"https:\/\/hydrauliccylindersprice.com\/th\/wp-json\/wp\/v2\/media?parent=2589"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/th\/wp-json\/wp\/v2\/product_brand?post=2589"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/th\/wp-json\/wp\/v2\/product_cat?post=2589"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/th\/wp-json\/wp\/v2\/product_tag?post=2589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}