Expanded Seal Flexibility with U-Plusâ„¢ Brackets

Viking Pump's latest generation of pumps (models H-QS in both steel and stainless steel) brings a range of improvements over the older alloy pumps, especially when it comes to sealing versatility. These new models expand the number of sealing options available within a single pump, while simultaneously cutting costs and reducing delivery times.

The bracket, a large component located behind the casing, includes a rigid cast-in foot for pump mounting. It houses the inboard shaft support bushing, the seal gland, and the outboard thrust control anti-friction bearing housing. By integrating features from the existing 123A, 127A, and 724 Series™ pumps, we’ve been able to introduce patented innovations such as the ability to use either stuffing box seals or behind-the-rotor seals in the same pump. That’s definitely value for money!

 

The new 123C and 127C Seriesâ„¢ models do not come with jackets, but Viking Pump also offers the 223C and 227C Seriesâ„¢ models with jacketed U-Plusâ„¢ brackets. These brackets allow for the circulation of steam or heat transfer fluids to melt ambient-temperature solids in the pump, such as resins, pitch, or chocolate. These models can be fitted with jacketed heads without relief valves, or with jacketed relief valves on non-jacketed heads.

Packing gland seals, O-Pro® Guard seals, component mechanical seals, cartridge mechanical seals, and cartridge multiple-lip seals are all available as stuffing box seals, each offering unique benefits depending on the application.

 

 

• Component mechanical seals are the most economical seal option and widely available, but they require careful installation to avoid damaging the seal faces. Standard flush lines from the discharge port to the seal area of the bracket help flush away solids and cool the faces.

 

• Cartridge type mechanical seals are pre-assembled as a single unit for easy installation into the pump stuffing box. The rotating part of the seal is secured to the shaft outside the stuffing box. Since the seal faces are not individually handled, issues caused by improper installation or handling are minimized. Single or double cartridge seals can easily adapt to API seal plans with barrier fluid to reduce fugitive emissions. Cartridge-type lip seals are also available, allowing replacement of individual lips to cut down on lifecycle costs. These seals have proven particularly effective in challenging applications like adhesive pumping.

 

Seals mounted directly behind the rotor were previously only available on the stainless steel 4724 Seriesâ„¢ and the cast iron 4124B Seriesâ„¢ pumps. They prevented any liquid from entering the bracket and were commonly used for liquids prone to solidifying between the bracket bushing and stuffing box seal. Now, these seals are available on all Next Generation models with U-Plusâ„¢ brackets, sizes H-QS, including Type 9 PTFE wedge seals for corrosive liquids up to 25,000 SSU (5,500 cSt).

 

 

The bearing housings remain unchanged from the original 123A/127A models and are threaded to allow adjustment of rotor end clearance within the pump. This lets users rotate the bearing housing to easily switch between very low and very high viscosity applications (or vice versa) without sacrificing efficiency. It also allows adjustments to compensate for rotor end wear over time, maintaining pump efficiency without needing to replace the rotor/shaft.

 

One major advantage of the U-Plus™ Bracket is its ease of switching between different sealing options. If a particular seal doesn’t meet user expectations for longevity or leak prevention, it’s simple to switch to another type of stuffing box or behind-the-rotor seal. These brackets are even retrofittable onto existing Viking 123A/127A/223A/227A pumps, with common mounting dimensions.