GESTRA UNA 45 hl Ball Float Steam Trap

The GESTRA UNA 45 hl Ball Float Steam Trap is a high-performance valve product of the GESTRA brand (part of the Spirax Sarco Group) designed for condensate discharge in steam systems, compressed air and gas mixtures. The valve utilizes advanced low friction rolling ball seal technology to ensure maximum sealing and durability for high flow condensate discharge scenarios independent of back pressure. As the horizontal left flow variant (hl for horizontal left) of the UNA 45 series, it is widely used in industrial steam systems, chemical and energy applications, providing reliable automatic drainage to avoid steam loss and condensate build-up.

Product Features

• Excellent sealing performance: Equipped with a rolling ball sealing unit and ball float control to ensure tight shutoff, prevent steam leakage, and improve system efficiency.
• Corrosion and dirt resistance: Material selection focuses on chemical resistance for a wide range of fluid environments, reducing the need for maintenance.
• Automatic ventilation function: DUPLEX control unit with integrated GESTRA 5N2 diaphragm regulator capsule for temperature-dependent automatic venting for saturated steam systems (superheated steam up to 5 K).
• Flexible Configuration: Supports SIMPLEX (manual venting), SIMPLEX-P (Perbunan rolling ball for DN 15-25), and internal bypass options for condensate, distillate, or rotating cylinder drainage.
• Optional Accessories: Includes a manual lift lever, manual vent valve, internal filter, sight glass cover, electrode mounting cover and smart-ready features to enhance ease of operation.
• General applicability: Unaffected by back pressure, suitable for Group 2 fluids (EU Pressure Equipment Directive), no intrinsic ignition source (ATEX compliant) to ensure safe use.

technical specification

• pressure rating: PN 40 / Class 300 with a maximum differential pressure (ΔPMX) of 2-32 bar (29-465 psi) depending on the orifice size (AO 2-32).
• Nominal size: DN 15, 20, 25, 40, 50, 65 (NPS ½"-2½"), supports a wide range of connections including flanged, threaded, socket welded and butt welded.
• temperature range: Up to 350°C (depending on pressure and control unit), DUPLEX for saturated steam +5 K, SIMPLEX-P up to 40°C.
• Volume Performance: Maximum capacity for hot condensate up to 10,000+ kg/h (depending on differential pressure and size), chilled water capacity 1-1.53 times the hot capacity. Detailed capacity charts are available in the official data sheets.
• Size and Weight Example(standard cover, flange PN 40):
  

  Nominal size (DN)	Length L (mm)	Width W (mm)	Height H (mm)	Weight (kg)
  15	150	171	150	6.8
  20	160	213	258	9.7
  25	230	186	258	8.5
  40	230	213	258	11.0
  50	230	213	258	12.0
  65	290	263	290	28.0
  (Increased width of the sight glass cover to 333 mm and weight increase of 1-2 kg).

Material Details

• valve body: 1.0460 (EN) / SA105 (ASME/ASTM), providing excellent strength and pressure resistance.
• Lids & Accessories: 5.3103 (EN) / A395 (ASME/ASTM), corrosion resistant design.
• gaskets: Graphite/CrNi to ensure reliable sealing.
• diaphragm capsule: Hastelloy/stainless steel for high temperature environments.
• Other components: Stainless steel to ensure long term durability. All materials comply with EN and ASME/ASTM standards for corrosive fluids (to avoid over-limiting chemical effects).

application scenario

The GESTRA UNA 45 hl steam trap is ideally suited for industrial steam system optimization, chemical condensate drainage, energy equipment drainage and compressed air systems. It ensures condensate discharge without steam loss and is suitable for high flow requirements such as saturated steam lines, rotary cylinders or distillation equipment. Easy to install, it supports horizontal or vertical position adjustment and is suitable for potentially explosive atmospheres (anti-static protection required). It is an efficient and reliable solution in steam system valve selection, helping to reduce energy consumption and maintenance costs.

Installation and Maintenance Guide

• mounting: Horizontal pipe installation, make sure that the flow arrows match the direction (hl is left) and that the name plate is up. Tighten with a torque wrench (cap screws 35-140 Nm). Provide space for maintenance (S=150-240 mm).
• safeguard: Clean the interior regularly (with water or suitable detergent) and replace the gaskets and control unit. Use VAPOPHONE® or TRAPTEST® to check functions. Troubleshooting: If leaking, check for dirt or damaged parts.

Related Documents

• GESTRA UNA 45/46/46A Datasheet PDF - Includes detailed specifications, capacity charts, and pressure-temperature ratings.
• GESTRA UNA 45/46/46A Operation Manual PDF - Provides installation procedures, safety instructions and maintenance guides.