Rethinking Valve Specification for LNG Liquefaction: A smarter alternative to rising stem ball valves

In LNG liquefaction plants, the dehydration of natural gas is a critical operation that can make or break downstream efficiency. Valves used in these processes - particularly those supporting molecular sieve systems - are often the unsung heroes of operational uptime. When they fail, the costs can be enormous.

Historically, Rising Stem Ball Valves (RSBVs) have been the go-to solution for these applications. But as operators face mounting pressure to reduce downtime, cut costs, and improve reliability, the limitations of RSBVs are becoming hard to ignore. Fortunately, high-performance alternatives are emerging.

Why valve performance matters in LNG dehydration

To safely and efficiently liquefy natural gas, moisture must be removed before cooling. Water in the system can freeze during liquefaction, causing serious damage to pipes and other infrastructure. This is where molecular sieve systems come in, using solid catalysts to absorb moisture as gas passes through.

Valves at the top and bottom of the dehydration towers control the thermal cycling process, alternating between purification and regeneration phases. These valves must handle:

Any failure in valve performance can cause process interruptions, expensive maintenance, and costly downtime. In one high-profile case reported by Reuters, unplanned LNG plant outages in 2022 led to losses reaching hundreds of millions of dollars.

The Case for Moving Beyond Rising Stem Ball Valves

RSBVs have served the LNG industry well, but their drawbacks are becoming more apparent:

As a result, LNG operators are exploring more cost-effective, compact, and low-maintenance alternatives that meet or exceed the performance of RSBVs.

Smarter Valve Solutions: Alternatives That Deliver

1. Double Eccentric Segmented Ball Valve – C-REX™

IMI’s C-REX™ valve is engineered to thrive in severe service applications like molecular sieve switching. Key features include:

With fast and effective maintenance, the C-REX™ helps minimise operational disruption and long-term cost.

2. Triple Eccentric Butterfly Valve – MV Series

IMI’s MV Series triple eccentric valve is another high-performance alternative designed for tight shutoff and low maintenance:

This valve’s resilience and serviceability make it ideal for operators focused on long-term value and performance.

Key criteria for specifying valves in LNG dehydration

When choosing valves for molecular sieve service, engineers should prioritise:

Making the switch

A growing number of LNG facilities are already transitioning to next-generation valve technologies. These facilities are seeing:

If your operation still relies on Rising Stem Ball Valves, now is the time to re-evaluate.