In short: a check valve that closes late slams shut against reverse flow and sends a pressure wave down the line. Non-slam designs close before the flow reverses. BTGC supplies KSB check valves, butterfly valves and gate valves for water transmission and power plant cooling water.

Saudi Arabia pumps potable water from coastal desalination plants to cities hundreds of kilometres inland, through some of the longest water transmission lines in the world. Every pumping station on those lines has check valves, and a check valve that slams is one of the most common causes of damage to pumps, pipes and supports.

Why check valves slam

When a pump stops, the water in the line decelerates and then starts to flow back. A conventional swing check valve closes only when reverse flow pushes the disc shut. By then the water is already moving backwards; the disc hits the seat and stops the column instantly. The result is a pressure spike, the bang that operators call slam, and over time cracked bodies, broken hinge pins and loosened pipe supports.

How a non-slam valve works

A non-slam check valve closes while the forward flow is still decelerating, before any reverse flow develops. Three design elements make this possible:

Nozzle check valves and spring-loaded dual-plate designs are the common non-slam types. For very long lines, the check valve is part of a surge protection scheme with surge vessels and controlled-closing butterfly valves.

KSB valves from BTGC

KSB of Germany is one of the world's largest manufacturers of pumps and valves and a leading supplier to the water and power sectors. The range BTGC supplies in the Kingdom covers:

• Non-slam check valves for large pumping stations

• Centric, double-offset and triple-offset butterfly valves for water, gas and process

• Gate and globe valves to DIN and ANSI standards for power plants and general industry

Applications in the BTGC catalogue are SWCC water transmission lines, power plant cooling water and general industry. See our page for KSB valves in Saudi Arabia and the full industrial valves offer.

Local content

Alongside KSB, BTGC supplies locally made water valves from AVK's Saudi facility and locally assembled Crane valves, so a water project can meet local content targets within one package. Ask BTGC to split the valve list between imported and locally made items.

BTGC support in Dammam, Jubail and Yanbu

BTGC supports water and power utilities from the Gulf and Red Sea coasts, with valve testing and repair at the service center in Jubail. For a quotation send the line size, pressure class, flow and the pump trip scenario; BTGC can arrange a surge study for the station.

Questions buyers ask

Is a dual-plate check valve non-slam? Spring-loaded dual-plate valves close quickly and are used as non-slam valves on many lines; for the largest pumps a nozzle check valve is the safer choice.

Can slam be fixed without replacing the valve? Sometimes with a damper or a spring upgrade; usually the lasting fix is a non-slam design.

Does BTGC supply the surge vessels too? Yes, surge vessels and controlled-closing butterfly valves are part of the water package.

Contact the BTGC valve team

Email valves@btc-ksa.com or call +966 13 856 0528. Branches: Dammam, Jubail and Yanbu. Request a quote.

In short: seawater destroys ordinary valves by corrosion, and large transmission lines destroy them by water hammer. A rubber-lined, double-eccentric butterfly valve answers both. BTGC supplies Nakakita Seisakusho Co., Ltd. butterfly valves up to 3000 mm for desalination and water transmission.

Saudi Arabia moves more seawater than almost any country on earth. Every desalination plant on the Gulf and the Red Sea takes in seawater through intake lines, passes it through pumps and membranes or evaporators, and sends potable water inland through pipelines that run for hundreds of kilometres. At every point a valve isolates, regulates or protects the line, and seawater attacks each one.

Two problems in one valve

Corrosion. Gulf seawater is warm and highly saline. Unprotected carbon steel pits within months; even some stainless grades suffer crevice corrosion. The valve seat and disc edge, where flow is fastest, go first.

Water hammer. When a pump trips or a valve closes too fast on a long line, the column of water keeps moving and then reverses. The pressure spike can crack valve bodies and lift pipe supports.

What a seawater butterfly valve needs

Nakakita valves from BTGC

Nakakita Seisakusho Co., Ltd. of Japan has built valves and fluid control systems since 1930. The range BTGC supplies in the Kingdom covers:

• Concentric and double-eccentric rubber-lined butterfly valves for seawater and utility service, up to 3000 mm

• High-lift safety valves for boiler and steam protection

• Remote control systems: hydraulic power units and consoles to operate valves in inaccessible places

• Cargo handling valve systems for liquid loading and unloading

In the Kingdom these valves serve desalination intake and outfall, water transmission lines and tank farm automation. See the range on our page for Nakakita valves in Saudi Arabia and the full industrial valves offer.

Non-slam check valves complete the line

A butterfly valve regulates and isolates; a non-slam check valve protects the pump when flow reverses. BTGC supplies both, so a pumping station can be specified as one package. Ask for the surge analysis with the valve offer on any long transmission line.

BTGC support in Dammam, Jubail and Yanbu

BTGC supports power and water utilities across the Kingdom from Dammam on the Gulf and Yanbu on the Red Sea, with the service center in Jubail for valve testing and repair. For a quotation send the line size, pressure rating, fluid (seawater, brine or potable), the actuation required and the closing time.

Questions buyers ask

Rubber lining or coating? A bonded rubber lining is thicker and resists abrasion from sand in the water; a coating is for lighter duty.

What closing time stops water hammer? It depends on the line length and velocity. BTGC can arrange a surge study for the pumping station.

Are spares held in the Kingdom? Seats and seals for common sizes are stocked; ask for the current list.

Contact the BTGC valve team

Email valves@btc-ksa.com or call +966 13 856 0528. Branches: Dammam, Jubail and Yanbu. Request a quote.