R016600x

Section I I - General Information

Table 2-3: Makeup water valve and pipe sizes

Make-up Valve

Minimum Line Size BHP

Make-up Valve

Minimum Line Size BHP

Make-up Valve

Minimum Line Size

BHP

(in.)

(in.)

(in.)

(in.)

(in.)

(in.)

25 35 50 75

3/4 3/4 3/4 3/4

3/4 3/4 3/4 3/4

150 3/4 200 3/4

1

500 600 700

1 1 2 2

1 1/2 1 1/2

1 1/4 1 1/4 1 1/4 1 1/4 1 1/4

250 300 350 400

1 1 1 1

2

1000

2 1/2

100 3/4 125 3/4

1 1

1500 2 1/2

3 4

2000

3

Note 1: All models use a makeup water solenoid valve. Note 2: Water flow is based on 44 lb. per hour per bhp (boiler horsepower). 2.8 Feedwater Supply Requirements

The feedwater supply line sizing will be a minimum of one line size larger than the inlet connection size of the Clayton reciprocating, positive displacement (PD), feedwater pump. Fractional dimensions will be rounded up to the larger whole-sized dimension.

NOTE Clayton takes advantage of the limited length and lower velocities to minimize its in- ternal line sizes. This common industry practice works well on Clayton’s internal pip- ing and pump head designs. The very short equivalent pipe lengths and quickly dividing flows (lower velocities) within our pump designs yields lower velocities and acceleration head. Unfortunately, the customer and installing contractor experience the reverse when designing their feedwater piping system. They are usually faced with much longer equivalent length pipe runs and/or have to deal with a pipe required to carry more than one generator’s flow. Therefore, it is critical for the installation designer to in- crease supply line sizes to meet Clayton’s requirements for velocity and acceleration head. See paragraph 2.8.2 and 2.8.3.

2.8.1 Multi-unit Systems In a multi-unit installation, Clayton recommends running separate supply lines to each feedwater pump. However, in some situations, it may be impractical to run separate supply lines. If a common supply line is chosen, Clayton suggests the following: • Make proper calculations to ensure velocities and head acceleration requirements are maintained. • If two or more pumps operate in parallel, with a common suction line, calculate the acceleration head for the common line by assuming that all pumps are synchronized, acting as one large pump.

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08/11/2016

Sect02_Genrl-xx4_t.fm