Gaoshan Valve — CS11H / CS41H Free Float Ball Steam Trap

Model: CS11H-16Q / CS41H-16Q / CS11H-25 / CS41H-25 / CS11H-40 / CS41H-40 | Pressure: PN16 / PN25 / PN40 | Connection: Threaded / Flanged | Medium: Steam, Condensate

Working Principle Animation

CS11H / CS41H Free Float Ball Steam Trap — Internal Structure & Full Operating Cycle

Product Overview

The CS11H / CS41H Free Float Ball Steam Trap is a premium mechanical steam trap that uses buoyancy force to achieve continuous, modulated condensate discharge. Inside the sealed body, a precision-ground stainless steel float ball rises and falls with the condensate level, automatically adjusting the valve orifice opening to match the incoming condensate load. Unlike thermodynamic disc traps that cycle intermittently, or thermostatic traps that rely on temperature sensing, the free float ball trap provides smooth, continuous drainage — ensuring that no condensate ever accumulates in the heat exchange equipment. This eliminates water logging, maximizes steam-to-product heat transfer efficiency, and provides exceptionally stable water flow in condensate recovery systems. The CS11H features female threaded connections for compact piping, while the CS41H offers flanged connections for larger installations. Three pressure classes (PN16, PN25, PN40) and two body materials (ductile iron QT450-10 and cast steel WCB) provide full coverage from low-pressure building heating to high-pressure industrial process steam. An integrated Y-series thermostatic air vent automatically removes both cold and hot non-condensable gases, preventing air binding and ensuring the trap remains fully effective from cold start to full operating temperature.

Key Advantages

Technical Specifications

Main Parts & Materials

Model Selection

Type A vs. Type B: Type A is the compact model for DN15–DN25 applications with limited space. Type B is the standard-capacity model covering DN15–DN50 with larger body dimensions and higher discharge capacity. PN40 models are available in Type B only.

How It Works

The CS11H/CS41H free float ball steam trap operates on the simple Archimedes buoyancy principle. Inside the trap body, a precision-ground stainless steel float ball rests freely in the condensate chamber. When the trap is cold (start-up), the Y-series thermostatic air vent is open, allowing air and cold condensate to be rapidly discharged. As condensate enters, the water level rises, and the float ball — being buoyant — rises with it. The float ball is mechanically linked to a discharge valve below; as the ball rises, it pulls the valve away from the seat, opening a precisely modulated orifice proportional to the condensate flow rate. When the condensate flow decreases, the water level drops, the float ball descends, and the valve closes smoothly toward the seat. If all condensate is discharged, the ball seats firmly against the orifice, providing steam-tight shutoff. This continuous, modulated action — with no snapping, no intermittent bursts, and no water hammer — ensures that condensate is discharged as fast as it forms, keeping heat transfer surfaces dry and operating at peak efficiency at all times. The Y-series thermostatic element works in parallel: it opens wide during cold start-up to purge air, then progressively closes as steam temperature rises, ensuring no air or non-condensable gases remain trapped in the system.

Dimensions — Type A (Compact, DN15–DN25)

Dimensions — Type B (Standard, DN15–DN50)

*Note: CS11H = threaded connection, CS41H = flanged connection. Type A for compact installations (DN15–25 only). Type B for standard capacity (DN15–DN50). PN40 models available in Type B only. Flange dimensions per GB/T 9113 / JB/T 79.

Installation Guidelines

• Install on a horizontal pipeline with the body oriented so the float ball rises and falls vertically (cover on top). Do not install at an angle or inverted
• Install a Y-type or basket strainer immediately upstream of the trap to protect the float mechanism and seat from pipe debris
• Provide a blow-down valve on the strainer for periodic cleaning without removing the trap assembly
• Install isolation valves on both inlet and outlet sides to allow trap removal without draining the steam system
• Install a sight glass on the trap outlet to allow visual confirmation of continuous, smooth condensate flow
• Ensure the condensate return line is adequately sized and vented to prevent back-pressure from exceeding the trap’s rated maximum
• For outdoor installations, insulate both the trap body and downstream condensate piping to prevent freeze damage
• During commissioning, verify that the Y-series air vent element opens during cold start-up and closes as steam reaches the trap
• Periodically inspect the float ball surface for signs of wear or pitting. The precision-ground finish should remain mirror-smooth for optimal sealing

Application Fields

Quality Standards & Certifications

• Design & Manufacture: GB/T 12247 (Steam Trap)
• Face-to-Face Dimensions: GB/T 12250
• Flange Ends: GB/T 9113 / JB/T 79
• Threaded Ends: GB/T 7306 / ISO 7-1
• Test & Inspection: GB/T 12251
• ISO 9001 Quality Management System Certified
• TS Special Equipment Manufacturing License
• 100% hydrostatic shell test at 1.5× rated pressure
• 100% float ball seat leakage test with water and air
• Y-series air vent element function test for each production batch

Packaging & Shipping

Each CS11H/CS41H free float ball steam trap is individually packed with protective threaded caps or flange covers, sealed in a poly bag with desiccant, and secured in a corrugated carton or plywood case. The float chamber and precision-ground ball are cushioned with foam inserts to prevent impact damage to the critical spherical sealing surface. All shipments include a packing list, material certificate, hydrostatic test report, air vent element function certificate, and installation manual. We support FOB, CIF, DAP, and other Incoterms.

After-Sales Service

• 18-month warranty from date of delivery under normal operating conditions
• Technical support for trap selection, sizing, condensate load calculation, and system design optimization
• Spare float ball assemblies, seat/orifice kits, and Y-series air vent elements available for field replacement
• Gasket and fastener replacement kits available for routine maintenance
• On-site inspection, trap audit, and performance survey service available upon request
• Free steam trap selection guide and condensate recovery system design consultation

Compare Gaoshan Steam Trap Series

Not sure which type fits your application? Compare all three Gaoshan steam trap series side by side to find the best match.

Steam Trap Selection Guide — Which Type Do You Need?

Not every application calls for the same trap type. Use this quick guide to identify the right Gaoshan steam trap for your specific operating conditions.