Inverted bucket steam trap - ES8N | Miyawaki

Miyawaki ES8N – Inverted Bucket Steam Trap

The Miyawaki ES8N is a mechanical inverted bucket steam trap constructed from ductile cast iron FCD450, designed for small to medium condensate loads in steam lines and process equipment. Its operation relies on the buoyancy of the bucket: the valve opens with condensate, while steam entry lifts the bucket, closing the seat. Discharge is intermittent or nearly continuous, depending on the condensate load.

Technical Specifications

• Sizes: DN15, DN20, DN25 / 1/2", 3/4", 1".
• Connections: Rc, NPT, or FF/RF flanges.
• Flanged versions: ASME/JPI 150/300 lb, DIN PN16, JIS 10K/16K/20K.
• PMA: 1.6 MPa.
• TMA / TMO: 350 °C.
• PMO: ES8N-5 at 0.5 MPa, ES8N-8 at 0.8 MPa, ES8N-16 at 1.6 MPa.
• Compliance: PED 2014/68/EU, Article 4, Section 3, without CE marking.

Construction and Operational Points

The SCCV System employs a self-centering valve assembly to limit mechanical stress on the seat. A small hole at the top of the bucket removes hot air and non-condensable gases, reducing air locking. The ES8N can be used in condensate return systems with back pressure up to 90% of upstream pressure, provided the installation includes a check valve and isolation valve at the outlet.

Applications

Suitable for heat exchangers, unit heaters, dryers, cleaning processes, dyeing facilities, and food/beverage industrial installations where condensate must be removed without electric or pneumatic actuators.

Installation and Maintenance

Installation requires horizontal flow with the nameplate on the top side. The steam trap should be positioned lower than the condensate-producing equipment, with a slight piping slope towards the inlet. Maintenance space of over 130 mm is needed, and line blow-off is required before startup.