Automatic Blowdown Controller

sample cooler.

2.9.11.1

Intermittent type boiler blowdown system rated for not less than 1724 kPa

(gage) 250 psig steam pressure.

2.9.11.2

Flow Assembly

Include a 25 mm one inch ball valve with 316 stainless steel ball and stem

and stainless steel electrode assembly.

2.9.11.3

Controller/Programmer

Include a conductivity meter with zero to 6000 micromhos range, valve

open/closed indicators and manual/auto control switch. Cycle interval and

sample duration shall both be adjustable over a wide range. Mount units at

operating floor near boiler front.

2.9.11.4

Accessories and Connections

a.

Continuous Blowdown Connection: At each boiler, provide a gate

valve and extend piping to header at flash tank.

b.

Header Connections: Provide with a tee with valved sampling

connection. Provide a20 mm3/4 inch, three globe valve bypass

around each flow assembly.

c.

Common Header: Provide from valved outlet connections on flow

assembly units to connection on flash tank.

2.9.11.5

Flash Tank

Designed for [_____]kPa (gage)psig and constructed in accordance with the

ASME BPVC SEC VIII D1. Tank shall be [_____]mminches in diameter by [_____]

mminches long including heads and shall be ASME Code stamped.

2.9.11.6

Blowdown Inlet

Provide tank with blowdown inlet, steam outlet, gage glass, float operated

outlet valve, relief valve, and inspection openings. Tank shall have steel

angle legs with plate feet for bolting to floor and legs shall be of

sufficient length so that bottom of lower head of tank will be not less than

460 mm 18 inches above floor.

2.9.11.7

Automatic Control System

Control level in the flash tank, by modulating a valve in the water outlet

line.

a.

Level Controller: External cage type air operated level

controller, complete with 40 mm 1 1/2 inch screwed connection, 350

mm 14 inch stainless steel float and Class 125 cast iron body.

Controller shall be direct acting with 20 to 103 kPa (gage) 3 to

15 psig range with proportional band. Locate controller to

maintain an operating level at center line of storage tank.

Provide level controller with air pressure reducing valve, filter,

gages and isolating valves for float cage. Provide unions on each

side of float cage.

SECTION 15511N

Page 68