Pipeline ancillaries for steam systems
Pipeline ancillaries may be small compared with major steam plant items, but they have a direct effect on steam system efficiency, reliability and maintainability. Across steam mains, pressure reducing stations, heat transfer equipment and condensate return lines, the right ancillaries help keep steam clean, dry and easier to manage.
Spirax Sarco pipeline ancillaries cover common duties such as air venting, non-return protection, moisture separation, dirt removal, visual inspection, vacuum breaking, controlled discharge and operating indication. Used correctly, they help protect downstream equipment. They also help reduce long-term maintenance cost.
Overview
Pipeline ancillaries are selected to solve recurring line-side problems that reduce steam system performance. Typical issues include non-condensable gases, entrained moisture, solid contamination, reverse flow, vacuum formation and discharge noise around steam release points. A well-matched ancillary arrangement helps protect sensitive downstream equipment such as pressure reducing valves, control valves, steam traps, flowmeters, heat exchangers and process vessels. It also supports better steam quality, more stable control and easier maintenance planning. The Spirax Sarco range includes air vents and air eliminators for gas removal, separators for moisture removal, strainers and filters for solid contamination control, check valves for non-return protection, sight glasses for visual inspection, vacuum breakers for vessel protection and diffusers for safer discharge to atmosphere. These products are used widely across steam distribution, condensate systems and process applications. They help plant teams troubleshoot faster and reduce avoidable failures caused by poor line condition. Where the duty extends beyond a single fitting, Spirax Sarco pipeline ancillaries can be selected alongside steam traps, control systems and application support resources. This helps build a more robust and serviceable steam system.
Spirax Sarco AVC32 Carbon Steel Air Vent
The AVC32 is a maintainable carbon steel balanced-pressure thermostatic air vent for removing air and other non-condensable gases from higher-pressure steam mains and high points on steam equipment.
Spirax Sarco AV13 Steam System Air Vent
The AV13 is a maintainable brass balanced-pressure thermostatic air vent for removing air and other non-condensable gases from steam mains and high points on steam equipment.
Spirax Sarco DCV3 Disc Check Valve
The Spirax Sarco DCV3 disc check valve is a stainless steel wafer non-return valve for steam, condensate, hot water and process pipework where compact reverse-flow protection is required.
Depressurisation valves
Spirax Sarco depressurisation valves provide controlled blowdown and discharge handling for steam systems where safer pressure release and operator protection matter.
Diffusers
Spirax Sarco diffusers help reduce blowdown noise by up to 80% and create a safer atmospheric discharge from steam traps, vents and blowdown points.
Hosedown stations
Spirax Sarco hosedown stations mix steam and water to provide instantaneous hot water for washdown, cleaning and sanitation duties.
Pressure and temperature gauges
Spirax Sarco pressure and temperature gauges provide clear local indication for steam systems, helping operators verify conditions and troubleshoot faster.
Separators
Spirax Sarco separators remove entrained moisture from steam, compressed air and gas systems to improve dryness, protect equipment and support process quality.
Sight glasses
Spirax Sarco sight glasses provide visual confirmation of flow, leakage and line condition to help operators troubleshoot steam systems faster.
Strainers and filters
Spirax Sarco strainers and filters remove solid contamination from steam systems to protect downstream valves, traps and control equipment while reducing maintenance.
Vacuum breakers
Spirax Sarco vacuum breakers protect steam systems and vessels from damaging vacuum conditions that develop during cooling, shutdown or condensate collapse.
How to choose pipeline ancillaries by operating problem
Pipeline ancillaries are usually selected by the operating problem they solve rather than by component family alone. The fastest route is to identify whether the main issue is reverse flow, moisture, dirt, trapped air, shutdown vacuum or noisy discharge, then move into the ancillary that corrects that condition first.
| Line-side problem | Typical ancillary route | Why it matters |
|---|---|---|
| Reverse flow or fallback risk | Check valves | Protects downstream equipment and helps limit flooding or waterhammer risk. |
| Entrained moisture | Separators | Improves steam or gas quality before it reaches sensitive equipment. |
| Solid contamination | Strainers and filters | Protects valves, traps, gauges and control hardware from debris. |
| Non-condensable gases | Air vents and air eliminators | Supports faster warm-up, better heat transfer and lower corrosion risk. |
| Vacuum or noisy discharge | Vacuum breakers and diffusers | Protects equipment during shutdown and improves discharge safety. |
Typical routes from common pipeline searches
Pipeline accessory searches usually start from the operating problem rather than from one product family name. Use steam check valves when the first concern is reverse flow, fallback or waterhammer risk. Review strainers when debris threatens downstream valve seats, traps or control hardware.
If the priority is steam dryness or moisture removal before sensitive equipment, move into steam separators. Use air vents when start-up air or other non-condensable gases are affecting heat transfer, and compare vacuum breakers when shutdown vacuum is the main protection issue.
Sales Brochures
| Document | Reference | Language | Download |
|---|---|---|---|
| Pipeline Ancillaries Overview | SB-GST-41 | English | Download |
Continue your steam system selection
Pipeline ancillaries are rarely selected in isolation. Venting, separation, filtration, indication and discharge control usually need to align with the wider steam system layout and operating duty.
Connect ancillaries with pressure and control duties
Review pressure reducing, surplus and process control duties when ancillary selection also depends on stable pressure management or downstream control performance.
Coordinate ancillaries with steam trap selection
Many line protection and venting decisions sit alongside condensate drainage strategy. Review the main steam trap families when the duty also depends on discharge performance.
Build application understanding before final selection
Use the technical knowledge centre when you need more context on steam distribution, steam quality, air venting, drainage or other application fundamentals behind the product choice.