The Spirax Sarco KBV21i and KBV40i key operated boiler blowdown valves consist of a carbon steel reduced bore ball valve with carbon reinforced PTFE seats and a key operated mechanism in stainless steel. Two types of keys are sold as optional extras: a standard length key and an extended length 'T' bar type key for use where access to the valve is limited. To ensure compliance with boiler regulations, the key cannot be removed when the valve is open.

TIP

It is recommended that an extended length 'T' bar type key is purchased for valve sizes DN50 and DN65 (2" - 2½").

Standards and Certification

These products comply with the requirements of the European Pressure Equipment Directive 2014/68/EU.

• ISO mounting in accordance with ISO 5211.
• Antistatic device complying with ISO 7121 and BS 5351.
• Available with certification to EN 10204 3.1 (must be stated at the time of order placement).

Sizes and Pipe Connections

DN25, DN32, DN40, DN50 and DN65 (1", 1¼", 1½", 2" and 2½") Flanged PN40 (F4), PN40 (BS) or ASME (ANSI) B 16.5 Class 300.

Flange	Face-to-face	Flange thickness
PN40 (F4)	DIN 3002 F4	EN 1092 Part 1
PN40 (BS)	BS 2080	EN 1092 Part 1
ASME (ANSI) 300	ASME B 16.10	ASME B 16.5

Pressure/Temperature Limits

KBV21i (PN40)

Body design conditions	PN40
PMA - Maximum allowable pressure	40 bar g @ 120 °C (580 psi g @ 248 °F)
TMA - Maximum allowable temperature	260 °C @ 0 bar g (500 °F @ 0 psi g)
Minimum allowable temperature	-29 °C (-20 °F)
PMO - Maximum operating pressure for saturated steam service	17.25 bar g (250 psi g)
TMO - Maximum operating temperature	260 °C @ 0 bar g (500 °F @ 0 psi g)
Minimum operating temperature	-29 °C (-20 °F)
ΔPMX - Maximum differential pressure	limited to the PMO
Designed for a maximum cold hydraulic test pressure of:	60 bar g (870 psi g)

KBV40i (ASME 300)

Body design conditions	ASME 300
PMA - Maximum allowable pressure	51 bar g @ 38 °C (740 psi g @ 100 °F)
TMA - Maximum allowable temperature	260 °C @ 0 bar g (500 °F @ 0 psi g)
Minimum allowable temperature	-29 °C (-20 °F)
PMO - Maximum operating pressure for saturated steam service	17.25 bar g (250 psi g)
TMO - Maximum operating temperature	260 °C @ 0 bar g (500 °F @ 0 psi g)
Minimum operating temperature	-29 °C (-20 °F)
ΔPMX - Maximum differential pressure	limited to the PMO
Designed for a maximum cold hydraulic test pressure of:	76.5 bar g (1110 psi g)

Materials

Part	Material	Standard
Body and insert	Zinc plated carbon steel	ASTM A216 WCB
Stem seals	Antistatic R-PTFE
Vented ball	Austenitic stainless steel	AISI 316
Stem (DN65)	Austenitic stainless steel	AISI 316
Stem (DN25 - DN50)	Martensitic stainless steel	AISI 420
Seats	Carbon and graphite reinforced PTFE	PDR 0.8

Valve Coefficients

Size	DN25 (1")	DN32 (1¼")	DN40 (1½")	DN50 (2")	DN65 (2½")
Kv value	30	40	81	103	197

For conversion: Cv (UK) = Kv x 0.963, Cv (US) = Kv x 1.156

Dimensions and Weights

Valve size	Flange	A	B	C	D	E	F	Weight
DN25 (1")	PN40 (F4)	125 (4.9)	119 (4.7)	35 (1.4)			19 (0.75)	3.9 (8.6)
	PN40 BS	165 (6.5)	119 (4.7)	35 (1.4)			19 (0.75)	4.1 (9)
	Class 300	165 (6.5)	119 (4.7)	35 (1.4)			19 (0.75)	4.3 (9.5)
DN32 (1¼")	PN40 (F4)	130 (5.1)	130 (5.1)	35 (1.4)			25 (0.9)	5.3 (11.7)
	PN40 BS	178 (7)	130 (5.1)	35 (1.4)			25 (0.9)	5.7 (12.6)
	Class 300	178 (7)	130 (5.1)	35 (1.4)			25 (0.9)	5.5 (12.1)
DN40 (1½")	PN40 (F4)	140 (5.5)	131 (5.2)	35 (1.4)			30 (1.2)	6.7 (14.8)
	PN40 BS	190 (7.5)	131 (5.2)	35 (1.4)			30 (1.2)	7.1 (15.7)
	Class 300	190 (7.5)	131 (5.2)	35 (1.4)			30 (1.2)	8.0 (17.6)
DN50 (2")	PN40 (F4)	150 (5.5)	139 (5.4)	35 (1.4)			37 (1.5)	9.0 (19.8)
	PN40 BS	216 (8.5)	139 (5.4)	35 (1.4)			37 (1.5)	9.9 (21.8)
	Class 300	216 (8.5)	139 (5.4)	35 (1.4)			37 (1.5)	10.1 (22.3)
DN65 (2½")	PN40 (F4)	170 (6.7)	140 (5.5)	35 (1.4)			50 (1.9)	12.4 (27.3)
	PN40 BS	241 (9.5)	140 (5.5)	35 (1.4)			50 (1.9)	13.9 (30.6)
	Class 300	241 (9.5)	140 (5.5)	35 (1.4)			50 (1.9)	15.0 (33.1)
Standard length key					32 (1.3)	258 (10.2)		0.4 (0.9)
Extended length 'T' bar key					500 (19.7)	375 (14.8)		0.9 (2)

Spare Parts

WARNING

The ball must be installed with the vent hole on the upstream side of the valve.

DN25 to DN50 (1" to 2")

Available spares	Item
Seats, insert 'O' ring and stem seals	5, 6, 9, 10
Insert tool - Required to aid the removal of the ball valve insert (2)	Not shown

DN65 (2½")

Available spares	Item
Seats, insert 'O' ring, seat 'O' ring, stem 'O' ring, lower stem seals and upper stem packing	5, 6, 7, 8, 11, 12
Insert tool - Required to aid the removal of the ball valve insert (2)	Not shown

Maintenance and Safety

DANGER

Before commencing any dismantling work on a boiler, depressurise, drain, and vent the boiler to atmosphere. Pipelines must be adequately isolated, depressurised, and drained. Ball valves can trap pressurised media in the body, so make sure there is no pressure to the valve body before loosening or removing the flange bolts.

Hydraulic Locking

Ball valves are prone to lock-up when used on certain heating/cooling applications where both steam and liquid will pass through the valve. This is caused by liquid trapped in the ball during closure being heated to create a high hydraulic pressure inside the ball cavity. To prevent this, a minute hole is drilled in the ball so that in the closed position, any excess pressure will be relieved. Spirax Sarco ball valves for these applications are clearly marked to allow the valve to be correctly installed, such that, when closed, the hole is facing the steam source.

Recommended Tightening Torques

Item no.	Part	Size	N m	lbf ft
2	Insert	DN25 and DN32	108 - 135	80 - 100
		DN40	135 - 160	100 - 120
		DN50	215 - 245	160 - 180
		DN65	245 - 270	180 - 200
15	Nut	DN25	17.5 - 20.3	13 - 15
		DN32, DN40, DN50 and DN65	34 - 40	25 - 30
	Key securing nut	DN25	17.5 - 20.3	13 - 15
		DN32, DN40, DN50 and DN65	34 - 40	25 - 30