{"id":2251,"date":"2026-06-25T08:01:03","date_gmt":"2026-06-25T08:01:03","guid":{"rendered":"https:\/\/hydrauliccylindersprice.com\/?post_type=product&p=2251"},"modified":"2026-06-25T08:01:03","modified_gmt":"2026-06-25T08:01:03","slug":"boom-aerial-work-vehicle-floating-hydraulic-cylinder-platform-levelling","status":"publish","type":"product","link":"https:\/\/hydrauliccylindersprice.com\/zh\/product\/boom-aerial-work-vehicle-floating-hydraulic-cylinder-platform-levelling\/","title":{"rendered":"Boom Aerial Work Vehicle Floating Hydraulic Cylinder \u2014 Platform Levelling"},"content":{"rendered":"
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<\/p>\n

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<\/div>\n
Boom Lift \u00b7 Platform Levelling \u00b7 Floating Cylinder \u00b7 Automatic Compensation<\/div>\n

Boom Aerial Work Vehicle
\nFloating Hydraulic Cylinder<\/h2>\n

The steering cylinder decides where the machine goes. The boom arm cylinders decide how high it reaches. But the floating cylinder decides whether the workers standing in the basket at the top can do their job safely \u2014 because it is the component that keeps the work platform level regardless of the boom angle. Every degree that the boom rotates changes the angle at its tip. Without the floating cylinder compensating for this angular change, the platform would tilt with the boom, and every adjustment the operator makes to boom height or reach would shift the footing of every person on the platform.<\/p>\n

\n
\n
\u03a663<\/div>\n
Bore (mm)<\/div>\n<\/div>\n
\n
60<\/div>\n
Stroke (mm)<\/div>\n<\/div>\n
\n
25<\/div>\n
MPa<\/div>\n<\/div>\n
\n
16 kg<\/div>\n
Weight<\/div>\n<\/div>\n
\n
UNF<\/div>\n
SAE Ports<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

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Technical Specification \u2014 GTHZ210C Floating Cylinder<\/h2>\n

\"Boom-Aerial-Work-Vehicle-Floating-Hydraulic-Cylinder-Dimensions-2\"<\/p>\n

\n\n\n\n\n\n
Cylinder Name<\/th>\nDrawing Number<\/th>\nBore (D)<\/th>\nRod (d)<\/th>\nStroke (S)<\/th>\nInstall Dist (L)<\/th>\nPressure<\/th>\nPorts (M)<\/th>\nWeight<\/th>\n<\/tr>\n<\/thead>\n
Floating Cylinder<\/td>\nGTHZ210C-620200-000<\/td>\n\u03a663<\/td>\n\u03a645<\/td>\n60<\/td>\n375<\/td>\n25 MPa<\/td>\n2-7\/8-14UNF<\/td>\n16 kg<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\n\n\n\n\n\n\n\n\n\n\n\n
Function<\/td>\nPlatform levelling \/ angular compensation<\/td>\n<\/tr>\n
Acting Type<\/td>\nDouble-acting (extend & retract for angular correction)<\/td>\n<\/tr>\n
Application<\/td>\nBoom aerial work vehicle \u2014 boom-tip platform levelling<\/td>\n<\/tr>\n
Body Material<\/td>\n20# \/ 45# \/ Q345B steel<\/td>\n<\/tr>\n
Port Standard<\/td>\n7\/8-14 UNF (SAE J514 \/ JIC 37\u00b0 flare)<\/td>\n<\/tr>\n
Seal Options<\/td>\nParker, NOK, Hallite, Busak Shamban<\/td>\n<\/tr>\n
Certification<\/td>\nISO 9001:2015, ISO 14001, ISO 45003<\/td>\n<\/tr>\n
Quality<\/td>\n100% pressure + leakage tested \u00b7 Certificate provided<\/td>\n<\/tr>\n
MOQ \/ Warranty<\/td>\n1 piece \/ 1 year<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n

<\/p>\n

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What Does a Floating Cylinder Do \u2014 Platform Levelling Explained<\/h2>\n

The work platform on a boom lift is mounted at the very tip of the boom. As the boom rotates upward, the angle at the tip changes \u2014 the platform would naturally tilt backward. As the boom rotates downward, the platform would tilt forward. Without correction, a boom raised from horizontal to 60\u00b0 elevation would tilt the platform 60\u00b0 \u2014 turning the floor into a ramp that no worker could safely stand on.<\/p>\n

The floating hydraulic cylinder corrects this tilt automatically. It is mounted between the boom tip and the platform bracket, and its extension or retraction adjusts the platform angle to compensate for the boom rotation. As the boom rises 10\u00b0, the floating cylinder extends a few millimetres. As the boom descends 10\u00b0, the floating cylinder retracts the same amount. The result: the platform stays level \u2014 or close to level \u2014 throughout the entire boom operating arc. This is why the cylinder is called “floating” \u2014 it does not hold the platform at a fixed position; it continuously adjusts to maintain a horizontal reference as the boom geometry changes beneath it.<\/p>\n

\"Boom<\/p>\n

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Why Only 60 mm of Stroke?<\/h3>\n

The platform levelling correction is a small angular adjustment \u2014 the floating cylinder does not lift or lower the platform through a large distance. On a boom with a tip-to-cylinder linkage arm of approximately 300\u2013500 mm, a 60 mm stroke translates to roughly \u00b16\u201310\u00b0 of platform angle correction. This covers the full useful compensation range for most boom lift operating arcs. The short stroke is an advantage, not a limitation \u2014 it means the cylinder is compact, lightweight, and can be integrated into the tight space at the boom tip without interfering with platform rotation or the jib section.<\/p>\n<\/div>\n

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Why 25 MPa Despite the Short Stroke?<\/h3>\n

The floating cylinder is positioned at the extreme end of the boom \u2014 the point of maximum moment arm. It must support the combined weight of the platform structure (200\u2013400 kg), the guardrails, the tool tray, and up to two workers with tools (maximum 230 kg per person). This entire load acts through a short lever arm at the boom tip, creating high reaction forces at the cylinder mounting point. The 25 MPa working pressure and the oversized \u03a645 rod (rod-to-bore ratio of 0.71 \u2014 significantly higher than a standard cylinder’s 0.5\u20130.6 ratio) ensure the floating cylinder can handle these concentrated tip loads without rod bending or buckling.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

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60 mm Stroke in Context \u2014 Comparison Across Boom Lift Cylinder Types<\/h2>\n

Every cylinder on a boom aerial work vehicle<\/a> has a different stroke \u2014 and that stroke directly reflects the function the cylinder performs. The floating cylinder’s 60 mm is the shortest stroke on the machine, because its job is the smallest physical movement: a few degrees of angular correction.<\/p>\n

\n\n\n\n\n\n\n\n\n\n
Cylinder Function<\/th>\nTypical Stroke<\/th>\nWhat the Stroke Produces<\/th>\n<\/tr>\n<\/thead>\n
Scissor lift raising<\/td>\n563\u20131,269 mm<\/td>\nMetres of vertical platform rise<\/td>\n<\/tr>\n
Boom lower arm<\/td>\n500\u20131,200 mm<\/td>\n60\u201380\u00b0 of boom rotation<\/td>\n<\/tr>\n
Boom upper arm<\/td>\n400\u2013800 mm<\/td>\n60\u201380\u00b0 of jib articulation<\/td>\n<\/tr>\n
Boom steering<\/td>\n200\u2013400 mm<\/td>\n\u00b135\u00b0 of front-axle wheel angle<\/td>\n<\/tr>\n
Platform floating<\/td>\n60 mm (this product)<\/td>\n\u00b16\u201310\u00b0 of platform angle correction<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n

<\/p>\n

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7\/8-14 UNF Ports \u2014 The SAE\/JIC Standard for North American Boom Lifts<\/h2>\n

The GTHZ210C floating cylinder uses 7\/8-14 UNF ports \u2014 the SAE J514 \/ JIC 37\u00b0 flare fitting standard that is dominant on North American-market boom lifts manufactured by companies such as JLG, Genie (Terex), and Snorkel. This is a different port standard from the M14\u00d71.5 metric ports used on the boom steering cylinder and the G1\/4 BSP ports used on the scissor lift range.<\/p>\n

The UNF thread is significant because it determines which hose fittings and adapters connect to the floating cylinder \u2014 the wrong thread standard means no connection, regardless of bore and stroke compatibility. When ordering the GTHZ210C as a replacement, verify that the existing hose fittings on the boom lift’s levelling circuit use 7\/8-14 UNF (37\u00b0 flare seat). If the existing fittings are metric or BSP, contact Korea Ever-Power<\/a> to specify the correct port thread for your platform \u2014 we produce this floating cylinder in UNF, BSP, and metric port variants on request.<\/p>\n

\"Double-acting<\/p>\n<\/section>\n

<\/p>\n

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The \u03a645 Rod \u2014 Why the Floating Cylinder Has the Thickest Rod Relative to Bore<\/h2>\n

Standard hydraulic cylinders have a rod-to-bore ratio of 0.5 to 0.6 \u2014 a \u03a663 bore cylinder would typically carry a \u03a632 to \u03a638 rod. The GTHZ210C floating cylinder carries a \u03a645 rod \u2014 a ratio of 0.71. This oversized rod is not an accident; it is a direct response to the loading conditions at the boom tip.<\/p>\n

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Buckling resistance at the boom tip<\/strong><\/p>\n

The floating cylinder holds the platform weight as a column load \u2014 the force pushes along the axis of the rod, and any lateral deflection at the tip can cause the rod to buckle. A thicker rod increases the critical buckling load by the fourth power of the diameter (Euler’s formula). The \u03a645 rod has 2.2\u00d7 the buckling resistance of a standard \u03a635 rod on the same \u03a663 bore \u2014 critical margin when the platform is loaded with two workers and the boom is at maximum extension where vibration amplitudes are highest.<\/p>\n<\/div>\n

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Reduced retract-side area for controlled response<\/strong><\/p>\n

A larger rod reduces the annular area on the retract side (bore area minus rod area). This means the floating cylinder extends faster than it retracts at the same flow rate \u2014 a deliberate asymmetry. When the boom rises (platform tends to tilt backward), the cylinder extends quickly to compensate. When the boom descends (platform tends to tilt forward), the cylinder retracts more slowly, providing a damping effect that prevents the platform from jerking forward as the boom is lowered. Workers on the platform experience this as smooth, predictable levelling.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

\"Boom-Aerial-Hydraulic-Cylinder-Application-1\"
\n<\/p>\n

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Boom Lift Floating Cylinder \u2014 Technical Questions<\/h2>\n
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The platform tilts noticeably when the boom is raised above 45\u00b0 \u2014 is the floating cylinder failing?<\/h3>\n

Possibly, but check the levelling linkage first. On most boom lifts, the floating cylinder works through a mechanical linkage that connects the boom, the cylinder, and the platform bracket. Worn linkage pins or a bent linkage arm can cause the levelling geometry to go out of specification \u2014 the floating cylinder extends the correct amount, but the worn linkage does not transfer the full correction to the platform. If the linkage is tight and the cylinder is leaking externally or internally (platform drifts off-level when the boom is held stationary), then the floating cylinder needs replacement.<\/p>\n<\/div>\n

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Is the floating cylinder actively controlled or passive?<\/h3>\n

On most boom lifts, the floating cylinder operates as part of a mechanically linked levelling system \u2014 the boom rotation mechanically drives the floating cylinder through a linkage, so the platform levelling is automatic and passive (no electronic control or sensor). Some advanced boom lift models use an active electronic levelling system with an inclinometer, a controller, and a proportional valve \u2014 on these machines, the floating cylinder is an actively controlled actuator. The GTHZ210C is suitable for both configurations; the difference is in the boom lift’s control system, not in the cylinder itself.<\/p>\n<\/div>\n

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Can I use a standard \u03a663 \u00d7 60 mm cylinder as a floating cylinder replacement?<\/h3>\n

Only if the rod diameter matches. A standard \u03a663 bore cylinder would typically have a \u03a632\u2013\u03a638 rod \u2014 significantly thinner than the \u03a645 rod on the GTHZ210C. The thinner rod has less buckling resistance and produces a different extend\/retract speed ratio, altering the levelling dynamics. On a personnel-carrying platform, these differences matter: the platform may level faster than expected in one direction and slower in the other, creating an uncomfortable and potentially unsafe tilt response. Always match the floating cylinder specification exactly \u2014 bore, rod, stroke, and port thread.<\/p>\n<\/div>\n

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Why does the floating cylinder use UNF ports when the other cylinders on the same boom lift use metric?<\/h3>\n

This is common on boom lifts that use a mix of hydraulic components<\/a> from different supply chains. The platform levelling assembly may be sourced from a North American supplier (who uses SAE\/JIC\/UNF fittings), while the boom arm cylinders and steering cylinders are sourced from Asian suppliers (who use metric fittings). It is not unusual for a single boom lift to have three different port standards across its cylinder population. When ordering replacement cylinders, always verify the port standard on the specific cylinder being replaced \u2014 do not assume all cylinders on the same machine share the same port thread.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

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Customer Reviews<\/h2>\n
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Mike H.<\/strong>
\nVerified Purchase \u00b7 May 2025<\/span><\/div>\n
\u2605\u2605\u2605\u2605\u2605<\/div>\n

Replaced the floating cylinder on a GTHZ210C telescopic boom \u2014 the original had developed a slow internal leak that caused the platform to tilt about 3\u00b0 forward over 5 minutes when the boom was held at 50\u00b0 elevation. Our guys in the basket were complaining their tools were sliding to one side. The Ever-Power replacement eliminated the drift completely. UNF ports matched, \u03a645 rod matched, 60 mm stroke matched. The platform now holds dead-level at any boom angle. Installed in about an hour \u2014 most of that time was bleeding the levelling circuit.<\/p>\n<\/div>\n

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Apex Access Solutions<\/strong>
\nVerified Purchase \u00b7 April 2025<\/span><\/div>\n
\u2605\u2605\u2605\u2605\u2605<\/div>\n

We service a fleet of 28 boom lifts for telecom tower maintenance. The floating cylinders are one of the harder parts to source because they’re specific to each boom model and not available from generic hydraulic suppliers \u2014 you need the exact rod diameter and port thread. Ever-Power is the first aftermarket supplier we’ve found who can match the \u03a645 rod and UNF ports correctly. We’ve installed 4 units over the past 3 months with zero issues. This saves us the 6\u20138 week wait and 2\u00d7 price from the OEM channel.<\/p>\n<\/div>\n

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Diego R.<\/strong>
\nVerified Purchase \u00b7 February 2025<\/span><\/div>\n
\u2605\u2605\u2605\u2605\u2606<\/div>\n

Cylinder is well-made. My only concern was that the levelling felt slightly faster on the extend stroke compared to the original \u2014 the platform snapped to level a fraction quicker when raising the boom. After about a week of use the difference was less noticeable, probably as the seals bedded in. The retract damping on lowering is actually better than the original \u2014 smoother transition. Overall a good replacement at a very competitive price. Four stars because of the initial extend-speed difference.<\/p>\n<\/div>\n

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Sunbelt MEWP Parts<\/strong>
\nVerified Purchase \u00b7 June 2025<\/span><\/div>\n
\u2605\u2605\u2605\u2605\u2605<\/div>\n

The floating cylinder is niche \u2014 most aftermarket suppliers don’t even stock it because the volume per model is low. Ever-Power manufactures to order at a price that makes stocking unnecessary \u2014 we order when we need it and receive it in 2\u20133 weeks. We’ve processed 6 floating cylinder orders for 3 different boom lift models. Every one has been dimensionally correct. The 25 MPa proof test certificate is included, which our safety inspectors require before any boom lift goes back into service.<\/p>\n<\/div>\n<\/div>\n<\/section>\n

<\/p>\n

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Other Boom Lift Cylinders<\/h2>\n
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\"Boom<\/p>\n

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Boom Steering Cylinder<\/h3>\n

\u03a663, 320 mm stroke, 21 MPa. Front-axle steering for boom lifts.<\/p>\n<\/div>\n<\/div>\n

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\"Boom<\/p>\n

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Lower & Upper Arm Cylinders<\/h3>\n

Boom rotation cylinders for articulating and telescopic platforms.<\/p>\n<\/div>\n<\/div>\n

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\"Scissor<\/p>\n

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Scissor Lift Cylinders<\/h3>\n

Lifting and steering for scissor-type aerial work platforms.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n<\/div>","protected":false},"excerpt":{"rendered":"

The floating cylinder is the reason the work platform stays level when the boom moves. Without it, the basket would tilt forward as the boom rises and backward as the boom descends \u2014 tipping tools off the platform, shifting personnel balance, and making overhead work dangerous. The GTHZ210C-620200-000 floating cylinder provides automatic platform levelling through a 60 mm stroke that compensates for the angular change at the boom tip as the boom rotates through its operating arc. At 25 MPa and \u03a663 bore, it supports the full weight of the platform, guardrails, tools, and two personnel at the extreme end of the boom \u2014 the point of maximum leverage. Korea Ever-Power manufactures this precision levelling cylinder with 7\/8-14 UNF SAE ports.<\/div>","protected":false},"featured_media":530,"comment_status":"open","ping_status":"closed","template":"","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":""},"product_brand":[],"product_cat":[849],"product_tag":[],"class_list":["post-2251","product","type-product","status-publish","has-post-thumbnail","product_cat-aerial-work-vehicle-hydraulic-cylinders","first","instock","shipping-taxable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/hydrauliccylindersprice.com\/zh\/wp-json\/wp\/v2\/product\/2251","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hydrauliccylindersprice.com\/zh\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/hydrauliccylindersprice.com\/zh\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/zh\/wp-json\/wp\/v2\/comments?post=2251"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/zh\/wp-json\/wp\/v2\/media\/530"}],"wp:attachment":[{"href":"https:\/\/hydrauliccylindersprice.com\/zh\/wp-json\/wp\/v2\/media?parent=2251"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/zh\/wp-json\/wp\/v2\/product_brand?post=2251"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/zh\/wp-json\/wp\/v2\/product_cat?post=2251"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/hydrauliccylindersprice.com\/zh\/wp-json\/wp\/v2\/product_tag?post=2251"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}