Home >> Filters >> Wedge Wire Screen >> Wedge Wire Tube & Cylinder
  • Scallops
  • Scallops
  • Scallops



The scallops assembly forms the outer screen component of a radial flow system. Its general shape extends parallel to the inner vessel wall using the wall as support. The inner surface delimits the outer side of the catalyst bed. 


Distribute and collect the flow. 

Retain catalyst and prevent catalyst leakage in radial flow device.

Product Details

Reactor Internals - Johnson Wedge Wire Scallops

Wedge Wire Johnson screen scallops, utilized within reforming reactors, are a cornerstone for catalyst retention in radial flow reactors. With a fan-shaped cross-section, these scallops safeguard the reactor's inner wall, ensuring efficient catalyst distribution and protecting against deformation during temperature spikes and pressure variations.

Key Features:

1. Fan-Shaped Design: The Johnson screen scallops boast a distinctive fan-shaped structure, providing optimal catalyst distribution within the reactor.

2. Higher surface area than the traditional outer screen

3. Safety Mechanism: Serving a dual purpose, the scallop acts as a safety mechanism, preventing damage to the centerpiece by relieving stress from compressive catalyst loads.

The scallop assembly forms the outer screen component of a radial flow system, installed within vertical reactors. Positioned against the inner vessel surface, these hollow conduits distribute and collect gas flow, ensuring even distribution across the catalyst bed.

Scallops support both outward and inward flow directions, with installation through the vessel's top manhole. The flow rate is determined by each scallop's cross-section area, collectively contributing to the total reactor capacity.


Ideal for various applications, including gas treatment, platforming, reforming, CCR, ammonia conversion, styrene, etc. 

Particularly valuable in catalytic reformers within petroleum refineries and the petrochemical catalytic industry.

Quality Assurance in Catalytic Reforming:

In critical processes like catalytic reforming, unexpected situations may arise, such as sudden shutdowns. Choosing high-quality wedge wire screen tubes is imperative to withstand external forces, ensuring compressive strength, flatness, and verticality. This guarantees stability and minimizes the risk of deformation, thereby optimizing catalytic reforming effects.

Enhance your reactor's performance and longevity with Johnson screen scallops – the industry standard for catalyst retention in radial flow reactors.

Get free Quote Scallops


YUANLV also supplies a variety of other screen and stainless steel vessel internals for petrochemical and refining applications include:

Screens for centerpieces, outer baskets, and regenerators;

Support Grid

Center pipe/Inner screen;

Header and laterals;

Filter elements

Related Products

whatsapp kf2 kf3 kf4