150 mm (6″) IBC Fill Cap with Fitted 2″ NPS/BSP Pressure & Vacuum Vent
Part No: IBC150P20BV027
This is a complete CPP® IBC lid assembly consisting of a 150 mm (6″) S160X7 female buttress-thread IBC fill cap with the HMVMN20MM027 2″ NPS/BSP pressure and vacuum relief vent already fitted.
Specification
- IBC lid size: 150 mm / 6″
- IBC lid thread: S160X7 female buttress thread
- Lid material: glass-filled polypropylene
- Lid seal: PP-based elastomer
- Vent: HMVMN20MM027 2″ NPS/BSP male pressure & vacuum relief vent
- Approximate vent air-in flow: around 100 L/min
- Configuration: complete lid and vent assembly
The vent is supplied fitted to the 6″ lid; this listing is for the complete assembly, not the lid and vent as separate loose items.
Important flow limitation
The fitted HMVMN20MM027 is a low-flow vent and is not intended to support rapid continuous emptying of a full 1,000 L IBC.
Because the vent admits approximately 100 L/min of replacement air, the liquid discharge rate must not exceed the vent's air-in capacity. For faster gravity discharge, pause after approximately 100–200 litres to allow the IBC to recover before continuing.
Many newer IBC bottles use thinner wall sections and can pull inward very quickly if negative pressure develops. If the container walls begin to deform during discharge, stop the flow immediately and allow the IBC to re-vent before continuing.
IBC pressure & vacuum caution
IBC leak testing may be carried out at relatively low positive pressure, often around 2–3 psi. This is a leak-test condition, not a working-pressure rating.
CPP® testing across different IBC designs has shown that standard IBC bottles can visibly bulge or move at relatively low positive pressure, while negative pressure can pull the side walls inward rapidly. The complete lid and vent assembly must therefore not be used to treat an IBC as a pressure vessel.
Fitted pressure & vacuum relief vent
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Vacuum relief - allows air into the IBC as liquid is discharged.
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Pressure relief - allows excess internal pressure to vent when pressure rises inside the container.
The vent has a glass-filled polypropylene body, PP-based elastomer seals and a 316 stainless-steel spring.
Next-generation CPP® IBC vent in development
CPP® is developing a new high-flow pressure and vacuum relief vent, with testing across a range of new and used IBC designs. Initial development results indicate substantially greater vacuum- and pressure-relief capacity than the current HMVMN20MM027 low-flow vent. Production release is targeted for the end of 2026, with final verified performance data to be published when testing is complete.
Use guidance
- Suitable for controlled gravity discharge and intermittent decanting.
- Do not assume the vent can match the full flow of an open IBC outlet valve.
- For sustained high-rate discharge, use a venting arrangement with sufficient verified air-in flow for the required liquid discharge rate.
Always confirm the IBC top thread and sealing arrangement before ordering, as lid connections can vary between IBC manufacturers and models.
The complete lid and vent assembly must not be used to pressurise an IBC beyond the container manufacturer's permitted operating limits.
