What We Do


We manufacture our own complete line of Cartridge, Assembly style Mechanical Seals for Industrial Pumps, Compressors, Mixers, Agitators, Reactors and Beadmill units.

We can repair / replace all makes & models of Mechanical Seals used on Pumps / Compressors / Mixers / Agitators / Reactors & Beadmill units. Custom Design / Manufacture Mechanical Seals for any application to increase run cycles. Provide Fluid Sealing Solutions for all industries.

We also provide Custom Engineered parts made from Tungsten Carbide, Silicon Carbide, Ceramic - for use in Shaft Steady Bushings / Wear Plates and many other industrial applications.


A chemical plant in Alabama sent a 95mm Netzsch double Beadmill seal in
for overhaul. It was in extremely poor condition. We had a new product side
wear plate made from solid Tungsten Carbide to replace the old Chrome
coated plate. Both rotary coated seats were replaced with solid Tungsten
Carbide seats. A new product side stationary Tungsten Carbide seal face
installed. On the outer end we machined a new Carbon Graphite stationary
seal face. A new rotary seal sleeve was made. The Netzsch double seal
uses two end caps that are installed around the Netzsch seal – we replaced
both of them, machined from 316 Stainless. The seal was re-assembled
& pressure tested to 80 psig for 15 min. – no pressure drop.

damaged Netzsch double Beadmill seal
damaged Netzsch double Beadmill seal
repair Netzsch double Beadmill seal
repair Netzsch double Beadmill seal

A pump company in Houston, Texas wanted a custom designed / manufactured
cartridge seal to install in a vertical pump for a municipal water district. They were
having issues with the original seals failing prematurely due to the pump shaft
steady bushings wearing out too quickly. We designed a cartridge seal that had a
heavy duty built in shaft steady bushing machined from a metallized carbon graphite
with built in internal channels to help increase fluid through around the bushing. This
seal has been running for 5 years – the original seals were failing after 4 – 6 months.
All the pumps in this municipal district have been overhauled and have the Robco
designed seals installed.

Custom Cartridge Seal for Vertical Pump
Custom Cartridge Seal for Vertical Pump in Service
Custom Cartridge Seal for Vertical Pump in Service
Custom Cartridge Seal for Vertical Pump in Service

A company in the Middle East contacted Robco of America to see if we could fix
some issues with a set of Pratt & Whitney turbine bearing seal assemblies. End
user was having issues with the quality of work being carried out at a repair facility
in Europe. We designed custom lapping equipment to rework the Carbon seal rings
and meet the required tolerances. The turbine bearing seal assemblies were shipped
back to the Middle East and are now in operation. End user informed Robco of America
they will send all future assemblies to us for overhaul.

Bearing Seal Assemblies
Bearing Seal Assemblies
Repaired Bearing Seal Assemblies
Repaired Bearing Seal Assemblies

A chemical processing facility in Louisiana called Robco of America in regards to a
failed lower steady bushing assembly in the bottom of a 15,000 Gal. mixing tank. We
went to the facility and told the customer we could replicate the assembly and improve
upon the materials of construction. We went with a Stainless outer stationary housing
and a Ni-Resist insert. Customer stated they were losing production for their largest
account and wanted the job expedited. We turned the job around in 36 hrs. by putting
in a nightshift. We made the recommendation to customer to have a spare bushing
assembly on site which they agreed upon.

Mixing Tank
Mixing Tank
Mixing Tank Bushing Repair

Chemical processing plant in Puerto Rico sent this 95mm double reactor seal with lower
glass lined flange in for overhaul. It has Kalrez o’rings for the high operating temps.
(440 deg. F.) Tungsten Carbide vs Silicon Carbide on product side. Carbon Graphite vs
Tungsten on outer end. Reason for seal failure was the worn lower shaft steady bushing
in the bottom of the 20,000 Gal. tank. This allowed the shaft to rotate outside of allowable
radial tolerances. We replaced the seal faces and seats. Machined a new double walled
seal housing which allows for the addition of cooling fluids to control temps. in the seal,
installed new Kalrez o’rings. Seal was re-assembled and pressure tested to 80psig for
15 min. – no pressure drop.

Double Reactor Seal
Double Reactor Seal
Double Reactor Seal
Double Reactor Seal Repaired by Robco of America

80mm Netzsch Double Mill Seal sent in for overhaul from chemical plant in Kentucky.
This unit had Silicon Carbide vs Silicon Carbide on both the product side and the outer end.
The Silicon Carbide seal faces & seats were chipped / cracked around the drive pin slots.
We advised the customer to upgrade material of construction to Tungsten Carbide which
is less prone to chipping / cracking. The end user agreed and we had new seal faces and
seats manufactured. Seal was repaired and pressure tested to 80 PSIG. Unit is now
back in operation.

Netzsch Mill Seal
Netzsch Mill Seal Stationary Faces
Netzsch Seal Repaired by Robco of America
Netzsch Seal Repaired by Robco of America

3.00” Double Mixer Seal sent in for emergency repair from chemical plant
in Pasadena Texas. Rotary Silicon Carbide seal faces were worn & chipped out. Stationary
product end Silicon Carbide seat was worn and chipped.

Rotary seal sleeve was worn and pitted on o’ring sealing surfaces, new sleeve required.
This seal has Kalrez o’rings on product end due to elevated operating temps. (+400F).
Robco of America had a repair kit on the shelf for this emergency overhaul. Seal was
turned around in (2) working days.

Double Mixer Seal
Mixer Seal Needs Repair

Chemical plant in North Carolina sent a failed 100mm Double Mixer Seal in for replacement.
We reverse engineered and provided a replacement mechanical seal unit. We upgraded the
product side seal faces to Tungsten vs Silicon from original Silicon vs Carbon. Seal has
been back in operation for 2 yrs.


Robco manufactured a new 4.00” double seal unit and reverse engineered the worn out
lower shaft steady bushing assembly. Robco oversaw the installation of both the
seal & bushing unit.


3.75" Robco EV05 single spring cartridge seals installed on (2) split case pumps – ready
to transport to North Carolina.


1.75" Robco seals being installed at airport fuel depot in Louisiana.


Thrust bearing & Pivot shoe set repaired & relapped flat within two Helium Light bands
for Deepwell Submersible Pump operating in Gulf of Mexico.


4.00" Robco EV07 Double Cartridge Seal being installed on a Reactor unit at a
chemical plant in south Texas.