Home | Seal Support Systems | API 682 plan 53B | Mechanical seal system SPB-590

Mechanical seal system SPB-590

A complete and fully functional Plan 53B system for arrangement 3 (3CW-FB, 3CW-BB, 3CW-FF) dual seals in accordance with API 682 or ISO 21049 latest edition – for shaft diameters ≤ 60mm and >60mm.

These high-end all butt-welded API 682 compliant units are best suited for the non-standard critical, hazardous and/or highly corrosive applications. Appreciating the need for sustainable and robust designs, without compromising performance, system construction primarily uses SS316L butt-welded piping and butt-welded piping components, except for the accumulator.

Compared to threaded or socket-welded piping constructions the butt-welded piping construction offers a  superior quality in strength and corrosion resistance.

The accumulator is a commodity item that is usually constructed from Cr/Mo steel using a Nitrile bladder and seals. Other materials available on request.

The highly efficient Flopac forced- or natural air draught seal coolers are constructed from SS316L seamless piping with full contact laser-welded SS316Ti cooling fins. Our range of TEMA C shell & tube seal coolers typically use SS316L piping with a SS316 bundle and CS shell.

Other materials available on request.

Standard configuration

Design PED 2014/68/EU (CE) – ATEX 2014/34/EU for a Zone 2 II/A T1-T3.
and/or ASME VIII – div. 1  w/o U-stamp.  

Suitable for general oil/water service – Non-hazardous, wetted parts AISI 316(L).

Design 40 barg @ -15/+90°C / ANSI 300#-sch.40s.

Seal supply and return connections ANSI WN RF ¾”–300#
Remainder ANSI WN RF 1/2″-300#. 

Engineering units: SI units, Bar/°C.
NDE: Visual-/hydrostatic and leaktesting
Surface preparation:  Flopac standard 

Including a SS316L/316Ti heat exchanger, Flopac type CNA-100 with a nominal capacity of 750 Watt.
Coolers with higher capacities available at request.  

Including one 4-20mA Smart/Hart® pressure indicating transmitter, installed complete with a SS316 instrument block/bleed valve.


Available at request:


Extended NDE packages to include inspections such as X-ray, LPE and P(A)MI.


Refer to the section ‘options’ below.

SPA-590 Configuration


Main components


One piping assembly

An all stainless steel 316/316L butt-welded piping construction with ANSI RF 300# Welding Neck flanges for all client connections.  



The fill-, vent- and drain connections are provided with a butt-welded valve. The fill connection is additionally fitted with a butt-welded non-return valve to prevent the accidental backflow of potentially hot and dangerous barrier liquid during filling operations. The nitrogen charge connection is a commodity item provided with a gas-valve. Further appendages as appropriate.


One pressure indicating transmitter

A 4-20mA Smart/Hart® pressure transmitter of high industrial quality with a 0.2% accuracy and including a  local display. Wetted parts SS316 with an IP 66 PU coated aluminium housing. Mounted on a (butt-welded) SS316 instrument block and bleed valve.


One natural air draught cooling section

A Flopac high efficiency CNA-100 natural air draught cooler, body material SS316L with full contact laser-welded 316Ti cooling fins(*1). Nominal capacity 750 Watt. Higher capacities available on request.

(*1) The full contact laser-welded 316Ti fins offer superior strength and a much better heat conductivity. 316Ti fins are well suited for offshore conditions.


Alternative material selections for specific services.

Flexible designs to fit a specific location or available space.


High pressure designs (ANSI 600# / 1500#) for static designs up to 200 barg.


Additional temperature- or flow instruments to enhance monitoring facilities.


Addition of a buffer liquid circulation unit; to ensure circulation and to enhance cooling capacity. 


Addition of an all stainless steel 5 ltr refill unit with 75cc/str handpump. (Other refill options available. Note: filling funnels should not be used!) 

Contact us


Westelijke Havendijk 15

4703 RA Roosendaal

The Netherlands


+31 (0)165 593 170